Conservation of energy on ramps, swings and coasters

Answer Key - Grade 11 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   A toy coaster cart starts at rest 6 m up a frictionless track and rolls down to 1 m up. With g = 9.8 m/s², how fast is it there, Ari, to the nearest tenth?

   9.9 m/s
2. 2.

   A toy coaster cart starts at rest 4 m up a frictionless track and rolls down to 1.5 m up. With g = 9.8 m/s², how fast is it there, Bo, to the nearest tenth?

   7 m/s

3. Read this first

   Energy of a 0.5 kg toy coaster cart at three points (example data)

   Point	Height (m)	Gravitational (J)	Kinetic (J)
   A	5	24.5	0
   B	2	9.8	14.7
   C	0	0	22

4. 3.

   Using the table, between which points does friction act on the cart, Jun?

   • Between A and B
   • Before point A
   • Nowhere, since energy is conserved
   • Between B and C
5. 4.

   Using the table, how much mechanical energy became thermal energy, Kira?

   • 0 J
   • 24.5 J
   • 22 J
   • 2.5 J
6. 5.

   Using the table, what is the cart's total mechanical energy at point B, Luz?

   • 14.7 J, the kinetic energy
   • 22 J
   • 9.8 J
   • 24.5 J
7. 6.

   Milo says a heavier cart reaches a higher speed at the bottom of a frictionless ramp than a lighter one. Agree or disagree?

   • Disagree: both reach the same speed
   • Agree: more weight means more speed
   • Agree: lighter carts lose more energy
8. 7.

   Noah says a pendulum bob released from 0.5 m swings higher than 0.5 m on the other side, with no friction. Agree or disagree?

   • Agree: it gains speed at the bottom, so it rises higher
   • Agree: a heavier bob swings higher
   • Disagree: it rises back to 0.5 m
9. 8.

   Pia says a cart's speed at the bottom of a frictionless track depends on the track's shape, not just its height drop. Agree or disagree?

   • Agree: steeper tracks give more speed
   • Agree: longer tracks give more speed
   • Disagree: the height drop sets the speed
10. 9.

    A toy coaster cart starts at rest 5 m up a frictionless track. Can it get over a hill 6 m high, Ren?

    • Yes, if the cart is heavier
    • No: it can't rise above its 5 m start
    • Yes, if it goes fast at the bottom
11. 10.

    With no motor after the start, why must the first hill of a toy coaster track be the tallest, Zee?

    • Gravity is weaker near the start
    • Later hills slow the cart less if taller
    • The cart can't climb above its starting height