Hi there!
Hi there!
We can begin by simplifying the work-energy theorem for Crate 2.
Since there is no friction, there is no energy dissipated. Thus, the initial energy is equal to the final energy.
Initially, we only have gravitational potential energy (U = mgh), and when the box has fully slid down, it only has kinetic energy (KE = 1/2mv²), therefore:
[tex]E_i = E_f\\\\mgh = \frac{1}{2}mv^2[/tex]
We can cancel out the mass and solve for velocity.
[tex]gh = \frac{1}{2}v^2\\\\v^2 = 2gh \\\\v = \sqrt{2gh}[/tex]
We must use right triangle trigonometry to solve for the HEIGHT given the ramp's length (hypotenuse).
We can use sine:
[tex]sin\theta = \frac{\text{h}}{L} \\\\Lsin\theta = h = 6 * sin(25) = 2.5357 m[/tex]
Now, solve for velocity.
[tex]v = \sqrt{2(9.8)(2.5357)} = 7.05 \frac{m}{s}[/tex]
Since this is 2.5 times the speed of the first crate, we know that the final velocity of crate 1 is:
[tex]v_1 = \frac{v}{2.5} = 2.82 \frac{m}{s}[/tex]
Crate 1:
In this instance, we have friction. Recall the following.
[tex]F_f = \mu N[/tex]
On an incline, the normal force is equivalent to the cosine of the force of gravity, so:
[tex]N = mgcos\theta[/tex]
Now, create an equation for the force due to friction.
[tex]F_f = \mu mgcos\theta[/tex]
The work done by any force is:
[tex]W = F \cdot d\\\\W_f = \mu mgdcos\theta[/tex]
In this instance, d = the ramp's length, or 6 m.
Now, we can use the work-energy theorem.
Ei = Ef
However, there is energy dissipated; we can call this Wf (Work due to friction). Therefore:
Ei - Wf = Ef
Now, we can rearrange to solve for Wf:
Ei - Ef = Wf
Like above, there is initially only GPE (U = mgh) and finally only KE (K = 1/2mv²), so:
[tex]mgh - \frac{1}{2}mv^2 = \mu mgdcos\theta[/tex]
Solve for the coefficient of friction. Begin by canceling out the mass and multiplying all terms by 2:
[tex]2mgh - mv^2 = 2\mu mgdcos\theta\\\\2gh - v^2 = 2\mu gdcos\theta\\\\\mu = \frac{2gh - v^2}{2gdcos\theta}\\\\\mu = \frac{2(9.8)( 2.5357)- (2.82)^2}{2(9.8)(6)cos(25)}[/tex]
Evaluate:
[tex]\boxed{\mu = 0.39}[/tex]
1. Allen is driving North on Highway 69 at 90 km/h and sees a large moose on the road. He
quickly slams on his brakes, but his reaction time is 0.85 s (as he sees the moose, thinks
about his response, and then presses the brake pedal). He presses the brake for 3.5 s and
comes to a stop just in time.
a) Find the distance travelled after seeing the moose and before pressing the brake.
b) Find the total distance he travelled before coming to a stop.
c) Find the average acceleration once he presses the brake.
Take the moment Allen sees the moose to be the origin.
First, convert his speed to m/s.
90 km/h = (90 km/h) • (1000 m/km) • (1/3600 h/s) = 25 m/s
(a) For the time it takes him to react (0.85 s), Allen is moving at a constant speed of 25 m/s, so that before he actually does anything, he covers a distance of
(25 m/s) • (0.85 s) = 21.25 m
(b) Once he presses the brakes, Allen's vehicle covers a distance x in time t of
x = 21.25 m + (25 m/s) t + 1/2 a t²
and has a speed v of
v = 25 m/s + a t
It takes him 3.5 s to come to a full stop. Use this to find the acceleration:
0 = 25 m/s + a (3.5 s)
a = - (25 m/s) / (3.5 s)
a ≈ - 7.1 m/s²
After 3.5 s, he will have traveled a total distance of
x = 21.25 m + (25 m/s) (3.5 s) + 1/2 (- 7.1 m/s²) (3.5 s)²
x = 152.5 m ≈ 150 m
(c) This one is worded a bit strangely, specifically "once he presses the brake" seems to suggest instantaneous acceleration, not average. Average acceleration is defined for some duration of time. You're probably expected to report the acceleration of the car as it comes to a stop, which we found earlier to be
a ≈ - 7.1 m/s²
Amoving object is in equilibrium. Which best describes the motion of the object if no forces change?
a. It will change directions.
b. It will slow down and stop.
c. It will maintain its state of motion.
d. It will speed up and then slow down.
What is an independent variable?
Define kinetic Energy and thermal energy. Describe what happens to each as the temperature of a substance is increases.
Explanation:
Kinetic energy is the energy by virtue of
object's motion whereas Thermal energy is
the internal energy of an object due to the
kinetic energy of its atoms.
On Increasing temperature, they both
increases
A block is 10cm long, 5cm wide and 2cm high and weighs 100g. What is the volume of the block? What is the density?
Answer:
1gm/cm^3
Explanation:
its the answer
A 6.0 kg object is moving at 5.0 m/s along the x axis in the positive direction. It collides
with and sticks to a 2.0 kg object moving also along the x axis. After the collision the
composite object is moving 2.0 m/s along the x axis in the negative direction.
Determine the velocity (magnitude and direction) of the 2.0 kg object before the collision.
Answer:
V2 = 23 [m/s] to the left.
Explanation:
In order to solve this problem, we must use the definition of conservation of linear momentum. That is, the momentum is conserved before and after the collision. The values before the collision will be taken to the left of the equality, and the values after the collision will be taken to the right of the equality, in this way we have:
Σbefore = Σafter
ΣPbefore = ΣPafter
where:
P = m*v
The positive momentum will be taken to the right and the negative momentum is to the left in this way we formulate the following equation:
[tex](m_{1}*v_{1}) + (m_{2}*v_{2})=-(m_{1} +m_{2})*v_{3}\\[/tex]
where:
m1 = mass of the first object = 6 [kg]
v1 = velocity of the first object = 5 [m/s]
m2 = mass of the stick = 2 [kg]
v2 = velocity of the stick [m/s]
v3 = velocity of the composite object = - 2 [m/s]
(6*5) + (2*V2) = - (6 + 2)*2
30 + (8*2) = - 2*V2
46 = - 2*V2
V2 = - 23 [m/s]
Note: the negative sign means the stick moves to the left
Energy from food
(Choose all that are correct )
Can be stored for later
Can be used to keep your heart beating
Can keep you warm
All of the above
Answer:
all of the above I think??
A ball is travelling 32° above the horizontal at a speed of 24 m/s. What is the horizontal component of its speed
A. 12.7 m/s
B. 13.0 m/s
C. 29.2 m/s
D. 20.4 m/s
Answer:
Since the ball is travelling 32 degrees above the horizontal, the value of Θ is 32
In the figure, v vector is the vertical component whereas h vector is the horizontal component
Using trigonometry:
CosΘ = h /24
Cos 32 = h/ 24
0.85 = h / 24
h = 24*0.85
h = 20.4 m/s
what is the order of magnitude of the final velocity of an object that begins from rest and accelerates at a rate of 20 meters per second2 for 5.0 seconds
The order of magnitude of the final velocity of an object that begins from rest and accelerates at a rate of 20m/s² for 5.0 seconds is 100m/s
The acceleration of a body is the change in velocity with respect to time as shown:
[tex]a=\frac{v-u}{t}[/tex]
Given the following parameters
a is the acceleration = 20m/s²
u is the initial velocity = 0m/s
t is the time taken = 5.0seconds
Required
Final velocity "v"
Substitute the given parameters into the formula:
[tex]20=\frac{v-0}{5} \\20 =\frac{v}{5}\\v = 20 \times 5\\v =100m/s[/tex]
Hence the order of magnitude of the final velocity of an object that begins from rest and accelerates at a rate of 20m/s² for 5.0 seconds is 100m/s
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metal sphere having an excess of +5 elementary charges has a net electric charge of
Answer:
[tex]q=+8.01\cdot 10^{-19}\ coulombs[/tex]
Explanation:
Elementary charge
The elementary charge, denoted by the symbol e is the electric charge carried by a proton or, equivalently, the magnitude of a negative electric charge carried by an electron, which has charge −e.
The value of the elementary charge is a fundamental constant in physics:
[tex]\mathbf{e}=1.60217662 \cdot 10^{-19}\ coulombs[/tex]
If a metal sphere has an excess of +5 elementary charge, then it has a net charge of:
[tex]q=5*\mathbf{e}=+5*1.60217662 \cdot 10^{-19}\ coulombs[/tex]
[tex]\boxed{q=+8.01\cdot 10^{-19}\ coulombs}[/tex]
At low pressures and high temperatures, the density of a gas
Answer:
Higher denisty
Explanation:
High pressure=high denisty
The magnitude of the vertical velocity vector for an upwardly launched projectile _________. a stays constant b gets smaller and then larger c decreases throughout the flight d increases throughout the flight
Answer:
changes by 9.8 m/s each second.
Why is a very small fraction (0.001%) of the water found in the atmosphere?
There is a very small fraction (0.001%) of the water found in the atmosphere due to evaporation of water.
What is Atmosphere?This is defined as mixture of gases surrounding the Earth or other celestial body, held in place by gravity.
A very small fraction (0.001%) of the water in the form of water vapor gas exist in the atmosphere due to evaporation by heat from the Sun.
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describe an example that shows thermal energy cannot be stored for a long time
Answer: heat always flows from higher temperature to lower temperature
Explanation: there:)
Heat always flows from higher temperature to lower temperature so can not be stored.
What is thermal energy?The energy present in a system that determines its temperature is referred to as thermal energy. Thermal energy flows as heat. Thermodynamics is a whole field of physics that studies how heat is transmitted across various systems and how work is performed in the process.
Heat dissipation always happen decrease in temperature so thermal energy can not be stored for long time.
Heat always flows from higher temperature to lower temperature so can not be stored
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we can see objecf in bright room because
Answer:
because there is a reflection due to light in the the room.
Explanation:
if if it's helped you please mark as brainliest and like and follow please
We can see objects in a bright room because, the object reflect the light falling on them
An image of the Earth-moon-sun system is shown.The moon remains in orbit around Earth because of the force of —
onsider what happens when you jump up in the air. Which of the following is the most accurate statement?A) Since the ground is stationary, it cannot exert the upward force necessary to propel you into the air.Instead, the internal forces of your muscles acting on your body itself propels the body into the air.B) The upward force exerted by the ground pushes you up, but this force can never exceed your weight.C) When you jump up the earth exerts a force F1on you and you exert a force F2 on the earth. You go upbecause F1 > F2, and this is so because F1 is to F2 as the earth's mass is to your mass.D) You are able to spring up because the earth exerts a force upward on you which is stronger than thedownward force you exert on the earth.E) When you push down on the earth with a force greater than your weight, the earth will push back with thesame magnitude force and thus propel you into the air.
Answer: D
Explanation: it seem right to me I really don't know if this right but I hope this helps
SAVE MEEEE WILL MARK BRAINLY
How much time would it take for a 0.17 kg ice hockey puck to decrease its speed by 9.0 m/s if the coefficient of kinetic friction between the ice and the puck is 0.05
How much time would it take for a 0.17 kg ice hockey puck to decrease its speed by 9.0 m/s if the coefficient of kinetic friction between the ice and the puck is 0.05
Given:- mass = 0.17 kg change in speed= 9 m/scoefficient of kinetic friction = 0.05 To Find :-Time taken to decrease the speed
Answer:-Equation :-
[tex]f {\tiny{k} }= u {\tiny{k}}.f \tiny{N}[/tex]
[tex]f {\tiny{N} }= mg = 0.17 \times 10 \\f {\tiny{N} }= 1.7 {N}[/tex]
[tex]u{ \tiny{N}} = 0.05[/tex]
[tex]mg = f {\tiny{k} }= u {\tiny{k}}.f {\tiny{N}} \\ 0.17a = 0.05 \times 1.7 \\ a = 0.05 \times \frac{ \cancel{1.7} {}^{ \: \: 10} }{ \cancel{0.17}} \\ a = 0.5m {s}^{ - 2} [/tex]
change in speed = 9 ms-1 (Given)
[tex]change \: in \: speed = at \\ 9 = 0.5 \times t \\ \frac{9 \times 10}{5} = t \\ \frac{9 \times \cancel{10} {}^{ \: \: 2} }{ \cancel{5}} = t \\ 18 \: sec = t \: [/tex]
A force of 3N acts on 90degree to a force of 4N.find the magnitude and direction of the resultant R.
R=A2+B2+2ABcosβ−−−−−−−−−−−−−−−−√R=A2+B2+2ABcosβ
A=4NA=4N , B=3NB=3N , β=90°β=90° , cosβ=0cosβ=0
R=A2+B2−−−−−−−√R=A2+B2
R=42+32−−−−−−√=25−−√=5NR=42+32=25=5N
tanα=Bsin90°A+Bcos90°=34tanα=Bsin90°A+Bcos90°=34
α=37°α=37°
Therefore the resultant of the two forces has a magnitude of 5N5N and is at an angle of 37°37° with respect to
Help real quick someone
The potential energy stored in the compressed spring of a dart gun, with a spring constant of 32.50 N/m, is 0.640 J. Find by how much is the spring is compressed. Submit Answer Tries 0/20 A 0.050 kg dart is fired straight up. Find the vertical distance the dart travels from its position when the spring is compressed to its highest position. Submit Answer Tries 0/20 The same dart is now fired horizontally from a height of 3.90 m. The dart remains in contact until the spring reaches its equilibrium position. Find the horizontal velocity of the dart at that time. Submit Answer Tries 0/20 Find the horizontal distance from the equilibrium position at which the dart hits the ground.
Answer:
A
[tex]x = 0.198456 \ m [/tex]
B
[tex]h = 1.3061 \ m [/tex]
C
[tex] v = 5.06 \ m/s [/tex]
D
[tex]d = 4.0273 \ m [/tex]
Explanation:
Considering the first question
From the question we are told that
The spring constant is [tex]k = 32.50 N/m[/tex]
The potential energy is [tex]PE = 0.640 \ J[/tex]
Generally the potential energy stored in spring is mathematically represented as [tex]PE = \frac{1}{2} * k * x^2[/tex]
=> [tex]0.640= \frac{1}{2} * 32.50 * x^2[/tex]
=> [tex]x = \sqrt{0.03938}[/tex]
=> [tex]x = 0.198456 \ m [/tex]
Considering the second question
From the question we are told that
The mass of the dart is m = 0.050 kg
Generally from the law of energy conservation
[tex]PE = mgh[/tex]
=> [tex]0.640 = 0.050 * 9.8 * h[/tex]
=> [tex]h = 1.3061 \ m [/tex]
Considering the third question
The height at which the dart was fired horizontally is [tex]H = 3.90\ m[/tex]
Generally from the law of energy conservation
[tex]PE = KE [/tex]
Here KE is kinetic energy of the dart which is mathematical represented as
[tex]KE = \frac{1}{2} * mv^2[/tex]
=> [tex]0.640 = \frac{1}{2} * 0.050 * v^2 [/tex]
=> [tex] v^2 = 25.6 [/tex]
=> [tex] v = 5.06 \ m/s [/tex]
Considering the fourth question
Generally the total time of flight of the dart is mathematically represented as
[tex]t = \frac{ 2 * H }{g}[/tex]
=> [tex]t = \frac{ 2 * 3.90 }{9.8 }[/tex]
=> [tex]t = 0.7959 \ s [/tex]
Generally the horizontal distance from the equilibrium position to the ground is mathematically represented as
[tex]d = v * t[/tex]
=> [tex]d = 5.06 * 0.7959[/tex]
=> [tex]d = 4.0273 \ m [/tex]
If you were to pour 4 different liquids into a glass and the liquids separated into 4 layers, which liquid would have the highest density?
A. the layer at the bottom of the glass
B. the third layer from the bottom of the glass
C. the layer at the top of the glass
D. the second layer from the bottom of the glass
Answer:
A.
Explanation:
The liquid with the higher density will be found at the bottom of the glass because is the heaviest of all. The liquids which have a lower density than the liquid at the bottom of the glass will be found at the top of the glass. We assume that the liquids are not soluble in each other because otherwise they will be mixed.
The ratio of carbon-14 to nitrogen-14 is an artifact is 1:3. Given that half-life of carbon-14 is 5730years, how old is the artifact?
Answer:
9155 years old
Explanation:
We use the following expression for the decay of a substance:
[tex]N = N_0\,\,e^{-k*t}[/tex]
So we first estimate the value of k knowing that the half-life of the C14 is 5730 years:
[tex]N = N_0\,\,e^{-k*t}\\N_0/2=N_0\,\,e^{-k*5730}\\1/2 = e^{-k*5730}\\ln(1/2)=-k*5730\\k= 0.00012[/tex]
so, now we can estimate the age of the artifact by solving for"t" in the equation:
[tex]1/3=e^{-0.00012*t}\\ln(1/3)= -0.00012*t\\t=9155. 102[/tex]
which we can round to 9155 years old.
True or false: humans have to find a balance with their environment, using sparingly so we don’t run out of them
Answer:
False
Explanation:
in my point of view the human race has adapted to being greedy in some ways we can save resources but its very rare
hope this helps! : )
e.) calculate the total heat required to change 10kg of ice at 0°c into water at 50°c.
Answer:
the heat change to 10kg of ice to water 0
so quantity of heat required is answer: 5460 J.
hope its helps!
Answer:
Q=ml+mc∆+ml'
=10*80+10*1*(100-0)+10*540
=800+1000+5400
=7200cal.7.2kcel
L=heat of fusion of ice
L'=heat of vapourisation of water
is water wet? If water is not wet does that make it dry?
Answer:
Water isn't wet by itself, but it makes other materials wet when it sticks to the surface of them.
Explanation:
Answer:
water is wet
it is a liquid
Explanation:
How far away is the light away in meters
299,792,458 is the right answer
If object A exerts a force on another body B, then body B exerts an equal and opposite for on body A. Which newton is this?
Answer:
newton 's 3rd law which states that to every action there's equal but opposite reaction
2. Calculate the work done by a 47 N force pushing a 0.025 kg pencil 0.25 m against a force of 23 N.
Answer: 6 J
Explanation:
Total force applied = 47 N Assuming that direction of movement of pencil and applied force is same. Work done by force in moving the pencil W = Force × Distance through which force moves ⇒ W = 47 × 0.25 = 11.75 J .-.-.-.-.-.-.-.-. In case we are asked useful work done then we calculate net force used for pushing the pencil: Net force used for pushing the pencil = 47 − 23 = 24 N Assuming that direction of movement of pencil and net force is same. Useful Work done by force in moving the pencil W u = Force × Distance ⇒ W u = 24 × 0.25 = 6 J
The work done the pushing force is required.
The work done by the pushing force is [tex]6\ \text{J}[/tex]
[tex]F_1[/tex] = Pushing force = 47 N
[tex]F_2[/tex] = Opposing force = 23 N
m = Mass of object = 0.025 kg
s = Displacement = 0.25 m
Work done is given by
[tex]W=F_ns[/tex]
[tex]\Rightarrow W=(47-23)\times 0.25[/tex]
[tex]\Rightarrow W=6\ \text{J}[/tex]
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A student claims that the cart can only be at rest if it is experiencing balanced forces. Choose the statement that correctly evaluates this student’s claim.
A.) The student is correct because only objects that are experiencing unbalanced forces can move.
B.) The student is correct because an object experiences balanced forces will remain at rest. C.) The student is incorrect because experiencing unbalanced forces can cause an object to come to rest.
D.)The student is incorrect because objects moving at a constant velocity is experiencing balanced forces.