15.53 the 50-lb package starts from rest, slides down the ramp, and is stopped by the spring. the coefficient of kinetic friction between the package and the ramp is if you want the package to be brought to rest 6 in from the point of contact, what is the necessary spring constant k?

The magnitude of the charge of the particle Q₁ is found to be 2.36 x 10⁻⁶ C.

The magnitude of charge Q₁ is 2.5 x 10⁻⁹ and the charge Q₂ is 0.2g and the separation between them is 5cm while the angle of attraction being  degrees.

Now, we can write,

If the force of attraction due to charge is F and the weight of the body is W.

Fcos(90-15) = W

KQ₁Q₂/R²cos(75) = Mg

Where,

K is the constant,

Q₁ and Q₂ are charges,

R is the separation in them,

M is the mass of Q₁,

G is the gravitational acceleration.

Putting values,

9x10⁹x2.5 x 10⁻⁹x0.92Q₁/(0.05)² = 0.2/1000 x 9.8

Q₁ = 2.36 x 10⁻⁶ C.

So, the charge of Q₁ is 2.36 x 10⁻⁶ C.

To know more about electrostatic force, visit,

https://brainly.com/question/20797960#:~:text=Expert%2DVerified%20Answer&text=The%20electrostatic%20force%20between%20two%20charged%20objects%20is%20directly%20proportional,distance%20between%20the%20two%20objects.

#SPJ4

The time required for one revolution is π²/2 seconds.

The time required for one revolution of an object moving on a circular path can be found by dividing the circumference of the circle by the speed of the object. One revolution typically refers to the complete circular movement of an object around another object or axis. The circumference of a circle is given by the formula

C = 2πr,

where r is the radius of the circle.

In this case, the radius of the circle is π meters, so the circumference is

C = 2π(π) = 2π

The speed of the object is 4.0 m/s, so the time required for one revolution is:
t = C/v

t = 2π²/4.0

t = π²/2.

To learn more about Time :

https://brainly.com/question/2364404

#SPJ11

The reason that for account for the slower-than-expected speed is the student did not account for the stretch of the rope caused by the weight of the ball. The correct option is e.

The speed of ball is slower than expected speed due to stretch in length of string. The swing rate of the pendulum is determined by its length. The longer the pendulum, whether it is a string, metal rod or wire, the slower the pendulum swings.

Mass of rope or ball does not effect speed, time period or frequency.

Frequency is the number of occurrences of a repeating event per unit time.  For clarity, also called temporal frequency, which is different from angular frequency.

To know more about the frequency, here

brainly.com/question/254161

#SPJ4

Objective resolving power if used in air is 661 nm/cm , the resolving power of the objective if it is used in an oil-immersion microscope is    = 963 nm/cm

The ability of an optical instrument, such as a microscope or telescope, to differentiate and separate two objects that are close together is known as its resolution power.

Part A :

Resolving power = 1.22λ/D

              = 1.22(550 nm)/(1.0 cm)

                       = 661 nm/cm

Part B :

Resolving power = 1.22λn(oil)/D

                        = 1.22(550 nm)(1.45)/(1.0 cm)

                                    = 963 nm/cm

It is established by comparing the instrument's aperture diameter to the wavelength of light utilized. The instrument's ability to differentiate between two close objects improves with increasing resolving power. A telescope's lens or mirrors focus light on a single point as it travels through them. The telescope's resolving power is based on how close the two points can be to each other before they are impossible to tell apart. More distant stars, galaxies, and other celestial objects can be seen in the image with a higher resolving power. In order to comprehend the universe and conduct scientific research, resolve power is absolutely necessary.

Learn more about Resolving power:

brainly.com/question/30432649

#SPJ1

Probability that mean of a sample of 36 observations, taken at random from this population, is less than 78 is approximately 0.9332.

According to the Central Limit Theorem, sampling distribution of mean will be approximately normal, regardless of shape of population, as long as the sample size is sufficiently large.

The formula for standard error :

SE = σ/√n

where σ is the population standard deviation, n is sample size.

SE = 12/√36 = 2

Finding the z-score for a sample mean of 78:

z = (x - μ) / SE = (78 - 75) / 2 = 1.5

Using a standard normal distribution table or calculator, Probability of getting a z-score less than 1.5 is  0.9332.

To Know more about Probability, here

https://brainly.com/question/30034780

#SPJ4

The bowling pin will take 1.79 seconds to return to the juggler's hand.

Assuming no air resistance, we can use the kinematic equation for vertical motion:

Δy = [tex]vi*t + (1/2)at^2[/tex]

where Δy is the change in height, vi is the initial velocity, t is the time elapsed, a is the acceleration due to gravity (which is -9.81 m/s^2), and we can set the final height to be equal to the initial height, since the bowling pin returns to the juggler's hand.

Therefore, we can write:

[tex]0 = vi*t + (1/2)at^2[/tex]

Substituting in the given values, we get:

[tex]0 = (8.80 m/s)t + (1/2)(-9.81 m/s^2)*t^2[/tex]

Simplifying and solving for t, we get:

[tex]t = (2*8.80 m/s) / 9.81 m/s^2[/tex]

t = 1.79 seconds

Therefore, the bowling pin will take 1.79 seconds to return to the juggler's hand.

To know more about Initial velocity, here

brainly.com/question/9365999

#SPJ4

1) Feature III is most likely the result of erosion from a river passing through the area.

2) Feature II is most likely the result of a magma deposit melting into the strata from below.

Erosion is the result of surface processes that move soil, rock, or dissolved material from one area of the Earth's crust to another, where it is deposited. Weathering, which involves no movement, is distinct from erosion.

3) Feature II is most likely the result of uplift due to faulting along a tectonic plate boundary.

6) Because water performs two functions that are crucial for fossils. The oxygen that would otherwise deteriorate them and cause them to decay or be consumed by organisms larger than bacteria is primarily blocked by the sediment that it carries to fill in the area around them.

The oxygen is completely blocked out as the sediments fill in further, and this causes the sediments to compact. The minerals in the water and sediments may then eventually migrate into the fossils due to pressure, heat, and primarily time.

This heavily depends on the passage of time because it is a very slow process, the quantity of minerals present because of the sediments' makeup, and the history of pressure and heat because that affects the mobility of the minerals.

Learn more about erosion

https://brainly.com/question/30587260

#SPJ1

A specific set of initial states that can be used for this purpose is the set of three Pauli matrices: |0⟩, |1⟩, |+⟩ = (|0⟩ + |1⟩)/√2, and |−⟩ = (|0⟩ − |1⟩)/√2.

By measuring the resulting polarization vectors for each of these four initial states, we can construct a set of four linear equations that can be used to solve for the unknowns completely.

We can then use these measurements:

[tex]P = ()P + č[/tex]

where P is a column vector containing the measured polarization vectors, () is the 3 x 3 real matrix representing the channel, and č is the constant vector. By measuring the resulting polarization vectors for each initial state, we can construct a set of linear equations of  form:

[tex]P_i = ()P_i + č[/tex]

To Know more about linear equation , here

https://brainly.com/question/11897796

#SPJ4

The correct statements for the focal point of a converging lens are:

A) A light ray entering parallel to the optical axis passes through the focal point on the other side of the lens.

C) A light ray passing through the focal point as it enters the lens goes through the focal point on the other side of the lens.

D) A light ray passing through the focal point as it enters the lens and exits the lens parallel to the optical axis.

A converging lens is a particular kind of lens that bends light in such a way that parallel light rays unite at a single focal point. Light bends towards the center of the lens because of its shape, which has a thicker center and a thinner edge. A distinct image is created at the focal point, which is where all of the refracted light converges. Common applications for this kind of lens include magnifying glasses, cameras, telescopes, and other optical equipment. Converging lenses—also known as convex lenses—may produce sharp, enlarged pictures because they can combine light. Converging lenses can be recognized by their form; they have a center that is rather thick.

To know more about a converging lens, check out:

https://brainly.com/question/29771989

#SPJ4

Based on the image given, the section where the planet will have the lowest average velocity is C since it is at the greatest distance from the Sun.

The correct option is D

Kepler's Second Law states that as a planet orbits the Sun, an imaginary line connecting them sweeps across the same amount of space at the same rate.

This means that planets do not travel along their orbits at a constant speed, rather, they move at varying speeds so that the line connecting the centers of the Sun and the planet covers the same amount of ground in the same amount of time.

Perihelion refers to the planet's point of closest approach to the Sun while the point of greatest separation is aphelion.

A planet moves fastest at perihelion and slowest at aphelion.

Learn more about Kepler's second law at:

#SPJ1

The following are as follow:

1. y component velocity:  5 m/s

2. the time it takes: 0.509 s

3. the velocity of the projectile: 10.2 m/s

4. the height: 1.28 m

1. Y component velocity:

At the initial angle of 60 degrees, the y-component velocity of the projectile is given by:

[tex]v_y = v_i sin(θ) = 10 m/s sin(60°) = 8.66 m/s[/tex]

At an angle of 30 degrees, the y-component velocity of the projectile is given by:

[tex]v_y = v_i sin(θ) = 10 m/s sin(30°) = 5 m/s[/tex]

So the answer is: 5 m/s

2. Time taken:

The time taken by the projectile to reach its maximum height is given by:

[tex]t = v_y/g[/tex]

At an angle of 60 degrees:

[tex]t = 8.66 m/s / 9.81 m/s^2 = 0.883 s[/tex]

At an angle of 30 degrees:

[tex]t = 5 m/s / 9.81 m/s^2 = 0.509 s[/tex]

So the answer is: 0.509 s

3. Projectile velocity:

The velocity of the projectile can be found using the x-component and y-component velocities. At the initial angle of 60 degrees, the x-component velocity and y-component velocity are given by:

[tex]v_x = v_i cos(θ) = 10 m/s cos(60°) = 5 m/s\\v_y = v_i sin(θ) = 10 m/s sin(60°) = 8.66 m/s[/tex]

The velocity of the projectile is given by the Pythagorean theorem:

[tex]v = sqrt(v_x^2 + v_y^2) = sqrt(5^2 + 8.66^2) = 10.4 m/s[/tex]

At an angle of 30 degrees, the x-component and y-component velocities are given by:

[tex]v_x = v_i cos(θ) = 10 m/s cos(30°) = 8.66 m/s\\v_y = v_i sin(θ) = 10 m/s sin(30°) = 5 m/s[/tex]

The velocity of the projectile is:

[tex]v = sqrt(v_x^2 + v_y^2) = sqrt(8.66^2 + 5^2) = 10.2 m/s[/tex]

So the answer is: 10.2 m/s

4. Maximum height:

The maximum height reached by the projectile is given by:

[tex]h_max = v_y^2 / (2g)[/tex]

At an angle of 60 degrees:

[tex]h_max = (8.66 m/s)^2 / (2 * 9.81 m/s^2) = 3.92 m[/tex]

At an angle of 30 degrees:

[tex]h_max = (5 m/s)^2 / (2 * 9.81 m/s^2) = 1.28 m[/tex]

So the answer is: 1.28 m

Learn more about projectile, here:

https://brainly.com/question/11422992

#SPJ1

The dependent variable in this experiment is the number of plants that can live in the water.

In an experiment, the dependent variable is the variable that is being measured or observed. It is the outcome variable that is affected by changes in the independent variable. In this case, the scientist is trying to determine how the amount of salt in the water affects the number of plants that can survive in the water.

Therefore, the number of plants is the variable that is being measured or observed, and it is the dependent variable in this experiment. The independent variable, in this case, would be the amount of salt in the water, which is being manipulated by the scientist.

To know more about the independent variable, here

brainly.com/question/28605199

#SPJ4

--The complete question is, A scientist conducted an experiment to determine how the amount of salt in a body of water affects the number of plants that can live in the water. In this experiment the dependent variable is--

Earth had essentially no atmosphere when it originated around 4.6 billion year ago out of a volatile mixture of gases and minerals. The ground had melted on it. An atmosphere developed while Earth cooled, primarily from gases emitted by volcanoes.

Approximately 78% of the gas in Upper orbit is nitrogen, while 21% is oxygen. In trace proportions, additional gases like carbon dioxide, neon, & hydrogen are also present in air.

In addition to providing us with the oxygenation we need to survive, it shields us from dangerous UV solar radiation. Without it, the pressure needed for liquid water to exist on the surface of our planet would not be possible. And it warm our globe, maintaining habitable temperatures.

To know more about Earth's visit:

https://brainly.com/question/3468253

#SPJ1

To derive the equation for the velocity vector as a function of time for the ball, we need to know the acceleration vector as a function of time. Once we have the acceleration, we can integrate it with respect to time to obtain the velocity.

Assuming that the ball is moving in a two-dimensional plane (i.e., the x-y plane), the acceleration vector can be expressed as:

a = ax(t) i + ay(t) j

where, i and j are unit vectors in the x and y directions, respectively. We can determine the expressions for ax(t) and ay(t) by applying Newton's second law of motion:

F = ma

Where, F is the net force acting on the ball, m is the mass of the ball, and a is its acceleration.

Let's assume that the ball experiences a net force of F = Fx i + Fy j, where Fx and Fy are the x and y components of the force, respectively. Then we can write:

F = Fx i + Fy j = ma

Equating the x and y components, we get:

Fx = m*ax

Fy = m*ay

Solving for ax and ay, we get:

ax = Fx/m

ay = Fy/m

Now we can integrate ax(t) and ay(t) with respect to time to obtain the expressions for the velocity components:

v_x(t) = v_{0x} + ∫ ax(t) dt

v_y(t) = v_{0y} + ∫ ay(t) dt

where v_{0x} and v_{0y} are the initial velocities in the x and y directions, respectively.

If we know the expressions for Fx and Fy as functions of time, we can substitute them into the above equations to obtain the velocity vector as a function of time for the ball.

Learn more about velocity vector here brainly.com/question/13492374

#SPJ4

The normal acceleration of a body travelling in a curved path is defined as the rate of change of its velocity vector. It is equal to the sum of the centripetal and tangential accelerations.

The magnitude of the normal acceleration is directly proportional to the radius of curvature, i.e a smaller radius of curvature implies a larger normal acceleration. Mathematically, the normal acceleration can be expressed as follows:

Normal acceleration = (v^2/r)

where v is the velocity of the body and r is the radius of the curvature. As the radius of the curvature decreases, the normal acceleration increases. Hence, the magnitude of the normal acceleration is directly proportional to the radius of curvature. On the other hand, it is inversely proportional to the diameter of curvature. The normal acceleration is also zero when the velocity of the body is constant. This happens when the body is travelling along a straight path. In such cases, the normal acceleration is zero since there is no change in the velocity vector in the direction perpendicular to the path.

To learn more about acceleration

brainly.com/question/12550364

#SPJ4

The correct solution to this question is that the magnitude of the normal acceleration is inversely proportional to the radius of curvature.

The curvature's reciprocal, R, is the radius of curvature in differential geometry. It is equal to the radius of the circular arc that, at that moment, most closely resembles the curve for a curve. The radius of curvature for surfaces is the diameter of a circle that fits a normal section or any combination of them the best.

The approximate radius of a circle at any given location or the curvature's vector length are both considered to be the radius of curvature of a curve. For any curve with the equation y = f(x), where x is a parameter, it exists.

Learn more about radius of curvature here brainly.com/question/30106465

#SPJ4

When a solid conducting sphere (or a disk in two dimensions) is charged positively, the positive charges are free to move within the sphere and distribute themselves evenly throughout the surface. This results in a uniform positive charge density on the surface of the sphere

conducting sphere will have the complete charge on its outside surface and the electric field intensity inside the conducting sphere will be zero. For a spherical charged Shell the entire charge will reside on outer surface and again there will be no field anywhere inside it.

charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. Positive and negative electric charges are the two types of charges commonly carried by charge carriers, protons and electrons. Energy is created by the movement of charges.

Examples of the types of charges are subatomic particles or the particles of matter: Protons are positively charged. Electrons are negatively charged. Neutrons have zero charge

To know more about conducting sphere visit:

https://brainly.com/question/12444946

#SPJ4

To solve this problem, we need to use the principle of equilibrium. The sum of all the forces acting on the boom in the horizontal and vertical directions must be equal to zero. The tension in cable AC is approximately 685.9 lb.

Let's start by resolving the forces in the vertical direction. The weight of the boom and the load is balanced by the vertical components of the tensions in cables AB and AC, which are equal to each other. Therefore:

232 + TAC sin(45) = P + 1000

where TAC is the tension in cable AC.

Next, we can resolve the forces in the horizontal direction. The horizontal component of the tension in cable AB is balanced by the horizontal component of the tension in cable AC. Therefore:

TAB cos(30) = TAC cos(45)

We are given the tension in cable AB, so we can solve for TAC:

TAC = TAB cos(30) / cos(45)

Substituting this expression into the first equation, we can solve for TAC:

232 + TAB cos(30) / cos(45)sin(45) = P + 1000

TAC ≈ 685.9 lb

Therefore, the tension in cable AC is approximately 685.9 lb.

In this problem, we have a boom or beam OA carrying a load P and being supported by two cables AB and AC. The tension in cable AB is given as 232 lb, and we are asked to determine the tension in cable AC.

To solve the problem, we can start by drawing a free-body diagram of the boom and cables. The weight of the load P acts downward, while the tensions in cables AB and AC act upward at angles θ1 and θ2 with respect to the horizontal. We can also draw a horizontal line representing the direction of the resultant force acting along the beam OA.

Learn more about equilibrium here:

https://brainly.com/question/11920396

#SPJ4

Arrangement based on material in universe: Dark Energy, Dark Matter, All matter in galaxies, all matter in planets.

In terms of the amount of material they represent in the universe, the components can be arranged as follows:

Learn more about universe here:

https://brainly.com/question/11987268

#SPJ4

"When the dipole moment of a dipole in a uniform electric field rotates to become more nearly aligned with the field, then the field does negative work and the potential energy increases." Correct option is C.

When the angle between the dipole moment and electric field is 180° then the potential energy of the electric dipole is maximum.

When the dipole is parallel to the external electric field, its potential energy is at its lowest. Additionally, it is highest when the dipole is opposed to the direction of the external electric field.

A torque is always experienced by an electric dipole in both a uniform and non-uniform electric field. However, a dipole will also suffer a net force of attraction in a non-uniform electric field. The electric dipole thus experiences both torque and force in a non-uniform electric field.

An electric dipole only feels torque in a homogeneous electric field. However, when the electric field is not uniform, torque as well as a net force are experienced.

To know more about dipole:

https://brainly.com/question/24170040

#SPJ4

The two quantities that should be graphed to yield a straight line whose slope could be used to calculate a numerical value for the charge to mass ratio of an electron are electric field strength and velocity.

Velocity is a vector quantity that describes the rate of change of an object's position in a given amount of time. It is typically measured in meters per second (m/s), but can also be measured in other units such as feet per second (ft/s) or kilometers per hour (km/h). It is a measure of both the speed and direction of an object's motion, and is distinct from speed, which is simply the rate of motion in a given direction. Velocity can be calculated by taking the derivative of an object's position with respect to time. It is an important concept in physics and is used to describe the motion of objects in a variety of situations. For example, in a car, velocity is used to determine the car's acceleration, and in an airplane, velocity is used to describe the airspeed.

To learn more about velocity

https://brainly.com/question/80295?source=archive

#SPJ1

The statement (temperature in celsius is a ratio scale; zero degrees celsius does not represent a complete absence of heat) is true.

The temperature in Celsius is not a ratio scale, as it does not have a true zero point that represents the complete absence of heat. The zero point of the Celsius scale is arbitrarily defined as the temperature at which water freezes at standard atmospheric pressure, but it does not indicate the complete absence of heat. Therefore, Celsius temperature is an interval scale, not a ratio scale.

The term "temperature" refers to a physical number that provides a quantitative expression of the qualitative concepts of warmth and chilliness. A thermometer is what is used to measure the temperature.

Want to know more about temperature visit the link which is given below;

https://brainly.com/question/7510619

#SPJ4

The expression for the charge density of a spherical cloud of charge of radius R and total charge +Q is given by:

p(r) = p0 for 0 ≤ r ≤ R

p(r) = 0 for r > R

Where p0 is the charge density at the center of the cloud, r is the distance from the center of the cloud, and C is a fundamental constant.

To derive an expression for p0, we can use Gauss' law to calculate the total charge within a sphere of radius r. Since the charge distribution is spherically symmetric, the electric field at any point outside the sphere is zero. Thus,

∫E·dA = Q/ε0

Where the integral is taken over a sphere of radius r, and ε0 is the permittivity of free space.

Using the divergence theorem, we can equate this to an integral of the charge density over the same sphere:

∫E·dA = ∫∇·p dV

Substituting in the expression for the charge density, we get:

Q/ε0 = ∫p0 (4πr2) dr

Integrating both sides and solving for p0, we get:

p0 = Q/(4πε0R3)

Learn more about Spherical cloud of charge or radius R:

https://brainly.com/question/14759319

#SPJ4

The heaviest box that can be pushed up the ramp at constant speed is the same as the weight of the box that can be pushed across the level floor at constant speed with the same force, since the force applied is the same in both cases.

This is because the force of gravity is the same for both boxes, and the force of friction is equal to the force applied in both cases, so the net force up the ramp is the same as the net force across the floor. Therefore, the heaviest weight box that can be pushed up the ramp at constant speed with the same force is w.

What is net force?

Net force is the total amount of force acting on an object. It is the combination of all the individual forces acting on an object. It is calculated by adding the individual forces together.

To learn more about net force

Here: https://brainly.com/question/12970081

#SPJ1

Based on Energy a) ΔS = -3.77 J/K b)  ΔS = 10.08 J/K c) ΔS_cold  = 6.31 J/K d) change in entropy of the Universe has to be positive

Based on Energy :

(a) To calculate the change in entropy of the hot reservoir, we can use the equation ΔS = Q/T, where ΔS is the change in entropy, Q is the amount of heat transferred, and T is the temperature in Kelvin. So, ΔS = -2.60 kJ / 690 K = -3.77 J/K.

(b) Using the same equation, we can calculate the change in entropy of the cold reservoir: ΔS = 2.60 kJ / 258 K = 10.08 J/K.

(c) To calculate the change in entropy of the Universe, we can add the changes in entropy of the hot and cold reservoirs: ΔS_univ = ΔS_hot + ΔS_cold = -3.77 J/K + 10.08 J/K = 6.31 J/K.

(d) The change in entropy of the Universe has to be positive in an irreversible process because the total entropy of the system and its surroundings always increases. The Second Law of Thermodynamics states that any process that occurs spontaneously (i.e. without external intervention) will always result in an overall increase in entropy. In this case, the heat transfer from the hot reservoir to the cold reservoir is an irreversible process, which means that the overall change in entropy of the Universe must be positive. If the change in entropy of the Universe were negative, it would imply that the process is reversible, which is not the case for an irreversible process. Therefore, the positive value for ΔS_univ in part (c) confirms that the process is irreversible.

Learn more about energy here:

https://brainly.com/question/1932868

#SPJ4

112mm is the length of mercury thread above ice point when the true temperature reads 58°C.

Mercury has the chemical symbol Hg and the atomic number 80. It was once known as hydrargyrum, derived from the Greek words hydor (water) as well as argyros (silver) (silver).

Mercury exists as the only lustrous metal known to be liquid at ordinary temperature and pressure. It is a hefty, silvery d-block element.

For difference of 100 degree Celsius = (96–2)= 94 mm length of mercury column

For difference of 75 degree Celsius = 94×58/100 = 18 mm length of mercury column

Total length of mercury column at 75 degree Celsius = 18+94=112  mm

Therefore, 112mm is the length of mercury thread above ice point when the true temperature reads 58°C.

To learn more about mercury, here:

https://brainly.com/question/25956102

#SPJ9

Option (d) A is false, B is true. Statement A is false and statement B is true. The relationship between the packing fraction and the binding energy is more complex and depends on the details of the nuclear interactions.

Statement B is true. The packing fraction is defined as the difference between the mass of the nucleus and the mass number of the nucleus divided by the mass number. It is a measure of the binding energy per nucleon in the nucleus.

However, statement A is false. The packing fraction is related to the binding energy per nucleon, but a larger packing fraction does not necessarily imply a larger binding energy. In fact, a lower packing fraction (i.e., a less tightly bound nucleus) can sometimes have a larger binding energy per nucleon than a nucleus with a higher packing fraction. The relationship between the packing fraction and the binding energy is more complex and depends on the details of the nuclear interactions.

Learn more about nucleus here: brainly.com/question/23366064

#SPJ4

The final velocity of the of the object is 60 m/s.

Velocity is the rate of change of displacement.

To calculate the speed of the object, we use the formula below

Formula:

Where:

Substitute these values into equation 1

Hence, the right option is b. 60 m/s.

Learn more about velocity here: https://brainly.com/question/24445340

#SPJ1

The position -time relation from the graph is given x = - 4t + 2t². Then , at t = 2.8 s, x have the value of 4.48 m. Therefore, the velocity being 1.6 m/s.

Velocity of an object is the measure of distance travelled per unit time. It is a vector quantity having both magnitude and direction. The magnitude of velocity is called speed of the object.

The instantaneous velocity of an object is its velocity at a particular instant of time.

Given the position- time relation of an object.

x = - 4t + 2t²

then at t = 2.8 s

x = 4 × 2.8 s + 2 ×(2.8 s)² = 4.48 m.

Then,

velocity = distance travelled / time

v = 4.48 m/2.8 s = 1.6 m/s.

Therefore, the instantaneous velocity of the particle is 1.6 m/s at t = 2.8 s.

Find  more on instantaneous velocity:

https://brainly.com/question/13190516

#SPJ9

First, we need to calculate the initial temperature of the water using the value of C. The initial temperature is (8.0 + C) oC.

Next, we need to calculate the mass of the water using the value of A, which is (15.0 + A) g.

To turn the water into ice, we need to remove the heat of fusion, which is the product of the mass of the water and the latent heat of fusion for water, which is 333 J/g.

Before the water can reach the freezing point, we need to remove the heat required to lower the temperature of the water from the initial temperature to 0 oC. We can calculate this using the specific heat of water, which is 4.186 J/g K.

Finally, we need to remove the heat required to lower the temperature of the ice from 0 oC to –(5.0 + B) oC. We can calculate this using the specific heat of ice, which is 2.090 J/g K.

We can add all these heat quantities to obtain the total heat that needs to be removed. The final answer should be given in kilo-joules (kJ) with 3 significant figures.

For more questions like Heat click the link below:

https://brainly.com/question/13962888

#SPJ4