Answers
Answer:
the answer is the third one since water reflects it
Explanation:
Related Questions
A 0.54 kg air hockey puck is initially at rest. What will it's kinetic energy energy be after a net force of 0.56 N acts on it for a distance of 0.84m?
Answers
Answer:
Kf = 470 mJ
Explanation:
According the work-energy theorem, the change in the kinetic energy of one object, is equal to the net work done on it.Since the puck is initially at rest, the change is kinetic energy is just the final kinetic energy of the puck.Assuming that the net force is horizontal, and causes a horizontal displacement also, we can find the net work on the puck as follows:[tex]W_{net} = F_{net} * \Delta X = 0.56 N * 0.84 m = 0.47 J = 470 mJ (1)[/tex]
As we have already said, (1) is equal to the final kinetic energy of the puck:⇒ Kf = 470 mJ (2)A light spring of force constant 3.85 N/m is compressed by 8.00 cm and held between a 0.250 kg block on the left and a 0.500 kg block on the right. Both blocks are at rest on a horizontal surface. The blocks are released simultaneously so that the spring tends to push them apart. What is the maximum velocity each block attains if the coefficient of kinetic friction between each block and the surface is:_______.
A) 0
B) 0.100
C) 0.463
Assume that the coefficient of static friction is larger than that for kinetic friction.
Answers
Answer:
A) v1 = -0.256 m/s
v2 = 0.128 m/s
B) v1 = -0.0642 m/s
v2 = 0 m/s
C) v1 = v2 = 0 m/s
Explanation:
We are given;
Spring constant; k = 3.85 N/m
Distance compressed; x = 8 cm = 0.08 m
Mass of left block; m1 = 0.25 kg
Mass of right block; m2 = 0.5 kg
A) From conservation of energy;
½kx² = ½m1•v1² + ½m2•(v2)²
Also from conservation of linear momentum, we know that;
m1v1 = m2v2
Now, v2 = m1•v1/m2
Plugging this for v2 in the first equation gives;
½kx² = ½m1•v1² + ½m2•(m1•v1/m2)²
Making v1 the subject, we have;
v1 = √(kx²(m2))/(m1•m2 + (m1)²))
v1 = √[(3.85 × 0.08² × 0.5)/((0.25 × 0.5) + 0.5²))
v1 = 0.256 m/s
This is the left block which is in the negative x direction and so v1 = -0.256 m/s
We saw that v2 = m1•v1/m2
Thus; v2 = (0.25 × 0.256)/0.5
v2 = 0.128 m/s
B) Force exerted by spring is;
F_s = kx = 3.85 × 0.08
F_s = 0.308 N
Normal forces will be calculated for both blocks as;
N1 = m1•g = 0.25 × 9.8 = 2.45 N
N2 = m2•g = 0.5 × 9.8 = 4.9 N
Let's calculate force of static friction for both blocks;
F_s1 = μN1 and F_s2 = μN2
We are given coefficient of friction as
μ = 0.1.
Thus;
F_s1 = 0.1 × 2.45 = 0.245 N
F_s2 = 0.1 × 4.9 = 0.49 N
F_s1 is lesser than F_s. Thus let's calculate the new compression;
x_1 = 0.245/3.85
x_1 = 0.06364 m
Thus, change in compression is;
Δx = x - x_1
Δx = 0.08 - 0.06364
Δx = 0.01636 m
From conservation of energy, since our coefficient of friction is not zero and we have frictional force, then we use the equation;
½k(x)² - F_s1•Δx = ½m1•v1² + ½k(x_1)²
Making v1 the subject, we have;
v_1 = √(k(x² - x_1²) - 2F_s1•Δx)/m1
v_1 = √(3.85(0.08² - 0.06364²) - 2(0.245 × 0.01636)/0.25
v1 = 0.0642 m/s
Since in negative x direction, then
v1 = -0.0642 m/s
F_s2 is greater than F_s. Thus, it means the right side block will not move and velocity is zero. v2 = 0 m/s
C) Coefficient of friction is now 0.463.
Thus;
F_s1 = 0.463 × 2.45 = 1.13435 N
F_s2 = 0.463 × 4.9 = 2.2687 N
They are both greater than F_s and thus no motion in both cases.
So v1 = v2 = 0 m/s
First you lift an object from the floor onto a shelf. Then you move the object back to the floor. do you perform the same amount of work each time? Explain.
Answers
A ball is rolling across the floor. Why does the ball come to a stop?
The force of gravity stopped it.
The force of friction stopped it.
The normal force stopped it.
It had too much mass.
Answers
Explanation:
the notmal focrce stopped it.
Answer:
It's C the friction stopped it
Explanation:
Gravity has a little effect on it. However the main force stopping the ball rolling is the friction force of the floor. The ball will stop rolling when the velocity of the ball is the same as the velocity of friction force.
PLEASE I REALLY NEED HELP!
Question 6
If the car traveled a total of 1,200 meters during this test, what was the average speed of the car? Include the
correct units.
Answers
Answer:
[tex]v=\dfrac{1200}{t}\ m/s[/tex]
Explanation:
Given that,
The car traveled a total of 1,200 meters during this test.
We need to find the average speed of the car. The average speed of the car is given by total distance covered divided by the time taken. So,
[tex]v=\dfrac{1200}{t}\ m/s[/tex]
But putting the value of t we can find the average speed of the car.
You serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 2.1 m/s. The
ball has ____
energy. Calculate it.
Answers
Answer:
4.6 Joules
Explanation:
K=1/2*MV^2
1/2 * 2.1kg * 2.1^2m/s
==4.6305 Joules
simplified to 4.6 Joules
How much is the frequency of gold?
Answers
Answer:
316 Hz
Explanation:
As for Frequencies of Elements, Gold is said to have 316 Hz
Answer:
The frequency of gold is 316 Hz
Explanation:
Since ancient times, gold is high valued and in the middle ages gold was experienced from the masters of alchemy not only for becoming rich, but also for healing purposes, as from Paracelsus and others.
A boy throws a rock with an initial horizontal velocity of 17.0 m/s and an initial vertical velocity of 21.0 m/s. How high above the boy's hand is the rock after 2.8 s?
Answers
Answer:
53.2
Explanation:
You can use the kinematic equation: displacement of x = (initial velocity + final velocity)*t/2
Subsititing: 17+21 = 38 * 2.8/2 = 53.2
Note: Displacement = distance between the 2 points
There are two categories of ultraviolet light. Ultraviolet A (UVA) has a wavelength ranging from 320 nmnm to 400 nmnm. It is not so harmful to the skin and is necessary for the production of vitamin D. UVB, with a wavelength between 280 nmnm and 320 nmnm, is much more dangerous, because it causes skin cancer.
Required:
a. Find the frequency ranges of UVA and UVB.
b. What are the ranges of the wave numbers for UVA and UVB?
Answers
Answer:
a) Remember the relationship:
v = f*λ
where:
v = velocity of the wave, remember that for an electromagnetic wave, this always is equal to the speed of light, then:
v = c = 3*10^8 m/s
f is the frequency of the wave
λ is the wavelength.
So if we want to compute the frequency, we have the equation:
f = c/λ
then:
We know that UVA has the range from 320 nm to 400nm, converting these to meters we hav:
1nm = 1m*10^(-9)
then:
320mm = (320*10^(-9)) m = 0.00000032 m
400nm = (400*10^(-9)) m = 0.00000040 m
Replacing these in our equation we can find that the range of frequencies is:
f = (3*10^8 m/s)/( 0.00000032 m) = 9.375*10^(14) Hz
f = (3*10^8 m/s)/( 0.00000040 m) = 7.5*10^(14) Hz
Then the range of frequencies is:
( 7.5*10^(14) Hz to 9.375*10^(14) Hz)
Similar for the case of UVB:
the wavelengths are:
280 nm to 320 nm
Rewriting these in meters we get:
280nm = 280*10^(-9) m = 0.00000028m
320nm = 320*10^(-9) m = 0.00000032 m
Then the frequencies are:
f = (3*10^8 m/s)/( 0.00000032 m) = 9.375*10^(14) Hz
f = (3*10^8 m/s)/( 0.00000028 m) = 1.07*10^(15) Hz
The range of frequencies for UVB is:
(9.375*10^(14) Hz to 1.07*10^(15) Hz)
B) We want to know the range of wavenumbers for both types of waves.
The wave number is calculated as:
1/λ
Which represents the number of waves in a given unit of length.
Then the range for UVA will be:
1/320nm = 0.0031 nm^-1
1/400nm = 0.0025 nm^-1
Then the range is:
( 0.0025 nm^-1, 0.0031 nm^-1)
And for the case of UVB we will have:
1/320 nm = 0.0031 nm^-1
1/280 nm = 0.0036 nm^-1
Then the range is:
(0.0031 nm^-1, 0.0036 nm^-1)
What is the power of 600j of work done in 4 seconds?
Answers
Explanation:
Power = change in work/change in time
P = 600 joules/ 4 seconds
P= 150 watts
hope this helps :)
A 0.38 kg drinking glass is filled with a hot liquid. The liquid transfers 7032 J of energy to the glass. If the
temperature of the glass increases by 22 K, what is the specific heat of the glass?
Answers
Answer:
841 J/kg.K
Explanation:
The computation of the specific hear of the glass is shown below:
As we know that
E= cmΔt
where
c denotes specific heat
m denotes 0.38 kg
Δt = temperature = 22k
E denotes energy = 7032 J
Now
7032 J = (0.38) (22) (c)
7032 J = 8.36 (c)
So C = 7032 J ÷ 8.36
= 841 J/kg.K
A Chinook salmon can jump out of water with a speed of 7.20 m/s . How far horizontally can a Chinook salmon travel through the air if it leaves the water with an initial angle of =29.0° with respect to the horizontal? (Neglect any effects due to air resistance.)
d=
Answers
Explanation:
The vertical component of the salmon's velocity is 7.2 m/s x sin 29 = 3.49 m/s
If g = 9.81 m/s^2, the salmon takes
(3.49 m/s) / (9.81 m/s^2) = 0.356 s to reach the highest point of its trajectory.
It takes another 0.356 s to fall back into the water again.
So the salmon is out of the water for a total of 0.712 s.
In this time the salmon travels horizontally with a velocity of 7.2 m/s x cos 29 = 6.30 m/s
We can now calculate the horizontal distance tavelled by multiplying the horizontal velocity by the time spent out of water;
0.712 s x 6.30 m/s = 4.48 m
Suppose that the acceleration of a model rocket is proportional to the difference between 160 ft/sec and the rocket's velocity. If it is initially at rest and its initial acceleration is 280 ft/sec22, how long will it take to accelerate to 128 ft/s
Answers
Answer:
Explanation:
Given ,
dv / dt = k ( 160 - v )
dv / ( 160 - v ) = kdt
ln ( 160 - v ) = kt + c , where c is a constant
when t = 0 , v = 0
Putting the values , we have
c = ln 160
ln ( 160 - v ) = kt + ln 160
ln ( 160 - v / 160 ) = kt
(160 - v ) / 160 = [tex]e^{kt}[/tex]
1 - v / 160 = [tex]e^{kt }[/tex]
v / 160 = 1 - [tex]e^{kt }[/tex]
v = 160 ( 1 - [tex]e^{kt }[/tex] )
differentiating ,
dv / dt = - 160k [tex]e^{kt }[/tex]
acceleration a = - 160k [tex]e^{kt }[/tex]
given when t = 0 , a = 280
280 = - 160 k
k = - 175
a = - 160 x - 175 [tex]e^{kt}[/tex]
a = 28000 [tex]e^{kt}[/tex]
when a = 128 t = ?
128 = 28000 [tex]e^{kt}[/tex]
[tex]e^{kt }[/tex] = .00457
Acceleration of a rocket model.
As acceleration is the change in the magnitude and direction of the moving body and refers to the increase in the velocity which varies over time. The acceleration of the model rocket is proportional to the r difference between the 160 feet/sec.
Thus the answer is 0.0457
The initial velocity of the rockset at the rest and the initial acceleration is about 280 fett/ sec then the length of acceleration for the rokst to reach 128 feet / sec. Will be calculated by the dv / dt = k ( 160 - v ).ln ( 160 - v ) = kt + c , where c is a constant, when t = 0 , v = 0 then putting the values , we have c = ln 160ln ( 160 - v ) = kt + ln 160, ln ( 160 - v / 160 ) = kt(160 - v ) / 160 = 1 - v / 160 = v / 160 = 1 - v = 160 ( 1 - ) acceleration a = - 160k given when t = 0 , a = 280 The 280 = - 160 k, k = - 175 a = - 160 x - 175 Hence a = 2800Thus 128 = 28000 = .00457.Learn more about acceleration.
brainly.com/question/13137118.
The temperature of stars in the universe varies with the type of star and the age of the star among other things. By looking at the shape of the spectrum of light emitted by a star, we can tell something about its average surface temperature.i)If we observe a star's spectrum and find that the peak power occurs at the border between red and infrared light, what is the approximate surface temperature of the star
Answers
Answer:
T = 3.6 10³ K
Explanation:
A good way to calculate the surface temperature of a star is to approximate it as a black body, and use Wien's displacement law.
λ T = 2,898 10⁻³
In this case they tell us that the light from the star is between red (700nm) and light infrared (2500nm) suppose that the radiation is
λ = 800 nm (near infrared)
T = 2,898 10⁻³ /λ
T = 2,898 10⁻³/ (800 10⁻⁹)
T = 3.6 10³ K
A spider accelerates from a standstill to 5m/s in 10s. What is its acceleration?
Answers
Answer:
Acceleration = 0.5m/s²
Explanation:
Given the following data;
Final velocity = 5m/s
Time = 10 seconds
Since the spider started from rest, its initial velocity is equal to 0m/s
To find the acceleration;
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
[tex]a = \frac{v - u}{t}[/tex]
Where,
a is acceleration measured in [tex]ms^{-2}[/tex]
v and u is final and initial velocity respectively, measured in [tex]ms^{-1}[/tex]
t is time measured in seconds.
Substituting into the equation, we have;
[tex]a = \frac{5 - 0}{10}[/tex]
[tex]a = \frac{5}{10}[/tex]
Acceleration = 0.5m/s²
What is the momentum of a 100-kilogram fullback carrying a football on a play at a velocity of 3.5 m/sec.
Answers
Answer:
100 Kg * 3.5 m/sec = 350 Kg-m/s
Explanation:
Momentum= F= Δ(mv) with m= mass, v= velocity, and Δ the change in mass and velocity
In this problem you are given all the factors you need to solve the equation you simply just plug in your mass (1,000 Kg) and Velocity (3.5m/s) and multiply them by each other to get your answer
An electric field of intensity 3.25 kN/C is applied along the x-axis. Calculate the electric flux through a rectangular plane 0.350 m wide and 0.700 m long if the following conditions are true. (a) The plane is parallel to the yz-plane. N · m2/C (b) The plane is parallel to the xy-plane. N · m2/C (c) The plane contains the y-axis, and its normal makes an angle of 30.5° with the x-axis. N · m2/C
Answers
Answer:
[tex]\varphi_1= 796.25 N m^2/C[/tex]
[tex]\varphi_2= 0 N m^2/C[/tex]
[tex]\varphi_3=686.1 N m^2/C[/tex]
Explanation:
From the question we are told that
Electric field of intensity [tex]E= 3.25 kN/C[/tex]
Rectangle parameter Width [tex]W=0.350 m[/tex] Length [tex]L=0.700 m[/tex]
Angle to the normal [tex]\angle=30.5 \textdegree[/tex]
Generally the equation for Electric flux at parallel to the yz plane [tex]\varphi_1[/tex] is mathematically given by
[tex]\varphi_1=EA cos theta[/tex]
[tex]\varphi_1=3.25* 10^3 N/C * ( 0.350)(0.700) cos 0[/tex]
[tex]\varphi_1= 796.25 N m^2/C[/tex]
Generally the equation for Electric flux at parallel to xy plane [tex]\varphi_2[/tex] is mathematically given by
[tex]\varphi_2=EA cos theta[/tex]
[tex]\varphi_2=3.25* 10^3 N/C * ( 0.350)(0.700) cos 90[/tex]
[tex]\varphi_2= 0 N m^2/C[/tex]
Generally the equation for Electric flux at angle 30 to x plane [tex]\varphi_3[/tex] is mathematically given by
[tex]\varphi_3=EA cos theta[/tex]
[tex]\varphi_3=3.25* 10^3 N/C * ( 0.350)(0.700) cos 30.5[/tex]
[tex]\varphi_3=686.072219 N m^2/C[/tex]
[tex]\varphi_3=686.1 N m^2/C[/tex]
Which plate is the South American plate?
Answers
Answer:
The south American plate
How do protons neutrons and electrons differ
Answers
Answer/Explanation:
They have a relatively small mass compared to Protons and Neutrons. Protons are electrochemically positive in charge and the Neutrons are electrochemically neutral in charge.
Answer:
They differ because
Proton means positive charge
Electrons are negatively charged
Neutrons are neutral
camouflage is to blend in with what
Answers
Answer:
Camouflage is a way of hiding. Blending in.
Explanation:
Look it up in a dictionary
Can someone help me grasp the concept of solving this please
Answers
Answer:
Q= m × c × change in tempQ= 1000 cal/kg × C Q= (5kg) × (1000 ) × (100-13) Q= 435000Hence 4.35 × 10^5 Ask any questions!I also do quizzes and exams if your interested!The degree of relationship between two or more variables is _________.
Answers
And the degree to which two variables vary together determines whether the relationship is strong or weak
In which situation would a bicycle rider NOT be accelerating?
If her direction changed and speed was constant.
If her speed decreased.
If her direction and speed were unchanged.
If her speed increased and direction was unchanged.
Answers
Answer:
If her direction and speed were unchanged.
Explanation:
Acceleration is a vector, so it has magnitude and direction.
If direction changes, acceleration exists.
If speed changes, acceleration exists.
1. An object that does not give off its own light is called ____
2. The tilt of the Earth's axis creates the
_______
3. Both of the movements of the Earth causes interesting changes on the _______
4. The word solar means of the ______
5. When the Sun, the Earth and the Moon are in line there is an/a _____
Answers
Answer:
1. non-luminous objects
sorry have to say the rest in the comments because brai.nly is doing the most for no reason
Explanation:
hope this helps sorry if it doesn't have a good rest of your day/afternoon :) ❤
A weightlifter lifts a weight of 500 N from the ground over her head, a distance of 1.8 m. How much work has been done to move the weight?
Answers
Hope this helps c:
A steel ball (mass = 50 grams) and a plastic ball of the same dimensions (mass = 10 grams) are dropped from the same height at the same time. Which of the following will occur? (ASSUME NO AIR RESISTANCE)
a. the plastic ball will hit the ground before the steel ball hits the ground
b. the steel ball will hit the ground before the plastic ball hits the ground
c. the steel ball and the plastic ball will hit the ground at the same time
Answers
I 2016 there were fewer pedestrians killed in traffic crashes than during the previous year
Answers
Radioactive strontium (Sr) is harmful to humans. Strontium, when ingested by cows, can be introduced to milk through the process of replacing an element of the same group or family that has similar properties. Using the Periodic Table, which element do you think can be easily replaced by strontium in milk?
A: B
B: Ag
C: Ca
D: K
Answers
Answer:
Ca
Explanation:
It is
One reason why it’s often easy to miss an action-reaction pair is because of the ________ of one of the objects.
Answers
Answer:
an action-reaction pair is because one of the objects is often much more massive and appears to remain motionless when a force acts on it. It has so much inertia, or tendency to remain at rest, that it hardly
a student holds a 3.0kg mass in each hand while sitting on a rotating stool. when his arms are extended horizontally, the masses are 1.0m from the axis of rotation and he rotates with an angular speed of 0.75 rad/s. if the student pulls the masses horizontally to 0.30m from the axis of rotation, what is his new angular speed
Answers
Answer:
Explanation:
Due to change in the position of 3 kg mass , the moment of inertia of the system changes , due to which angular speed changes . We shall apply conservation of angular momentum , because no external torque is acting .
Initial moment of inertia I₁ = M R² = 3 x 1 ² = 3 kg m²
Final moment of inertia I₂ = M R² = 3 x .3 ² = 0.27 kg m²
Applying law of conservation of angular momentum
I₁ ω₁ = I₂ ω₂
Putting the values ,
3 x .75 = .27 x ω₂
ω₂ = 8.33 rad / s
New angular speed = 8.33 rad /s .