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Conservation of Energy

Last updated over 5 years ago

6 questions

20

Question 1

1.

20

20

20

1

1

A 3.5 kg toy dump truck moving with a speed of 1.7 m/s starts up a ramp. How high (h) does the truck roll before it stops? 

Question 2

2.

A 2.0-kilogram ball rolling along a flat surface starts up a hill. If the ball reaches a height of 0.93 meters, what was its initial speed?

1.86

3.51

4.27

Question 3

3.

You are on in-line skates at the top of a small hill. Your potential energy is equal to 2,000 J. The last time you checked, your mass was 70.0 kg. If you start rolling down this hill, your potential energy will be converted to kinetic energy. At the bottom of the hill, your kinetic energy will be equal to your potential energy at the top. Calculate your speed at the bottom of the hill. (Number only. Round to the nearest tenth ex: 3.2)

Question 4

4.

A squirrel has 75 joules of kinetic energy and 25 joules of gravitational potential energy at one point during its fall from a fence to the ground. An instant before striking the ground, how much mechanical energy does the squirrel have? (number only)

Question 5

5.

If the PE at point A is 2000 J and the cart's mass is 50kg, find the velocity at point D (halfway up the ramp). What is the best way to solve this problem?

Since the PE at the top equals the KE halfway down the ramp. Use 2000 J in the KE formula and solve for v.

Since v = PE times the mass, multiply 2000 times 50. Use that in the PE formula and solve for v.

Since the PE at the top divided by 50 equals the KE at point D, divide 2000 by 50 and then use that in the KE formula to solve for v.

Question 6

6.

A 70 kg skydiver is falling through the sky at 52 m/s. He is currently 680m above the ground. What is the skydiver’s total mechanical energy?

94,640 J

466,480 J

561,120 J

371,840 J

2.51

Since the PE at the top equals the KE at the bottom, halfway up the KE will be 1000 J. Use that in the KE formula and solve for v.