Stored (potential) energy
Grade 8 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Ari lifts a 2 kg backpack onto a shelf 3 m above the floor. Use PE = m × g × h with g = 10 N/kg. How much stored energy does it gain?
Bo lifts a 4 kg box of books onto a closet shelf 2 m up. Use PE = m × g × h with g = 10 N/kg. How much stored energy does it gain?
A teacher helps Esme raise a 3 kg bucket 5 m with a pulley. Use PE = m × g × h with g = 10 N/kg. How much stored energy does it gain?
Jun puts the same ball on a low shelf (A, 0.5 m) and a high shelf (B, 2 m). Which stores more energy?
- A, since it is easier to reach
- Neither: a still ball has no energy
- B, the higher shelf
Kira holds a skateboard still at the top (P) and middle (Q) of a ramp. Where does it store more energy?
- Neither, since it is held still
- At Q, where it would move faster
- At P, the higher point
Milo stretches a rubber band and holds it still. What kind of energy does it store?
- Sound energy
- Elastic stored energy
- Motion energy, since it could fly off
- No energy, since it is still
Pia holds two magnets a little apart; they pull toward each other. What kind of energy do they store?
- Thermal energy
- Motion energy
- No energy until they snap together
- Magnetic stored energy
Ren drops a ball. Read the bar chart. How much motion energy does it have just before landing?
- 0 J
- 30 J
- 15 J
Read this first
Use this
Energy bar chart (example data), one bar per energy store, height in J. Band stretched: elastic stored 12 J; motion 0 J. Toy just leaves the band: elastic stored 0 J; motion ?. A transfer arrow goes from elastic stored to motion, labeled launch. Friction and sound are small enough to leave out.
Tala launches a foam toy with a stretched band. How much motion energy does the toy have as it leaves?
- 6 J, half used up
- 0 J, the band used it
- 12 J
Zee swings at the park. How much motion energy does Zee have at the lowest point?
- 200 J
- 100 J
- 0 J