Download Name: Period:______ Work, Energy and Power Review For

Name:__________________________
Period:______
Work, Energy and Power Review
For questions 1-5 refer to the image below.
1) If a marble was released from the track at point A, would it complete the course? If not where would the marble stop
or reverse course?
2) If there is no friction what happens to the total mechanical energy in the marble?
3) Describe what type of energy the marble has at point B.
4) The marble on the tack has the most kinetic energy at point B, what has happened to that kinetic energy when the
marble is at point E?
5) Draw the KE and PE of the marble as it goes through this course both on the same energy vs time graph.
6) In real life no machine is 100% efficient. Why is no machine 100% efficient?
For questions 7 & 8 refer to the image below.
7) Before the man pulled on the rope the shoe had no kinetic energy. After the pulled the rope the shoe had kinetic
energy. Where did the energy come from?
8) The man in the picture pulled on the rope with 90 J of energy and the shoes (5kg) was moving at 5m/s when it hit him.
How much energy was lost to heat in the machine?
9) Name all the equations for work and explain what they mean.
10) Below is a graph of a bungee jumpers height vs time, circle on the graph the points which his KE was zero.
11) What is the equation of gravitational energy and explain what it means?
12) If Mr. Vickery (100kg) is standing on top of the first story of the school (5m high) how much poetential energy does
he have?
13) If Mr. Vickery then climbs to the second story (11m high) what is the difference in potential energy when compared
to the first story?
14)Which object has the most potential energy?
15) You throw 4 different objects, which objects have the same kinetic energy?
16) If all the objects in the problem above were traveling at 2m/s, how would their kinetic energies compare?
17) How much potential energy does a skydiving dachshund (11kg) have as he jumps out of a plane at 3,810 m?
18) What is the dachshounds velocity before he hits the ground in the previous problem? (assume no parachute and no
friction)
19) A 30 N sled is pulled over ice by a rope with a horizontal tension of 50N. If the sled is pulled 10 m, what was the
change in kinetic energy?
20) A 110,000 kg train traveling at 25 m/s takes 1610 m to come to a complete stop in 130 seconds. What is the work
done to stop the train?
21) If you push a 1,000 kg car with 73N of force and the car moves 13 m, how much work do you perform?
22) If you push a 1,000 kg car with 35N of force but it does not move, how much work do you perform?
23) If you push a 1,000 kg car with 50N of force and the car moves 8m, can you calculate your power? If so what is your
power? If not what else do you need to know to calculate it?
24) If Pat and Sam both lift a 100N weight 2m but Pat does it in less time then Sam, who was more powerful and why?
Who did more work and why?
25) If a 60 kg student runs up some stairs that are 7m high and they do it in 29.4 seconds, what is their power?
26) How much power does a strong man need to lift three 200 kg weights up a 22 m tower in 385 seconds?
27) How much work did the strong man do in the previous problem?
28) A car mechanic uses a lever to lift a 3,000 N engine 1.3 m up from a car in 3.7 seconds. How much power did the
machine output?
29) Mr. Vickery could not find a parking spot one morning when he was running a little late, thinking that he was
superman he decided he would just lift another car out of its spot. Mr. Vickery is not superman and no matter how hard
he tried he could not lift a car. How much work did Mr. Vickery do? How much power did he output?