Stored (potential) energy
Grade 8 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
A 5 kg box is lifted onto a loading dock and gains 150 J of stored energy, Bo reads. With g = 10 N/kg, how high was it lifted?
A pulley raises a 3 kg bucket for Esme's tree house, giving it 240 J of stored energy. With g = 10 N/kg, how high was it lifted?
Jun moves a box to half the height, then adds a second identical box on top. How does the stored energy compare?
- It is zero: the boxes are still
- It is the same as before
- It doubles: the load is heavier
- It halves: height is what counts
A 3 kg pot sits on a 2 m shelf and a 2 kg pot on a 3 m shelf. Which stores more energy, Kira?
- They store the same
- The pot on the 3 m shelf
- The 3 kg pot
- Neither, since both are still
Read this first
Three objects on shelves (example data)
object mass (kg) height (m) P 1 6 Q 3 1 R 2 4 Luz's table lists three objects on shelves. Which stores the most energy from gravity?
- P, the highest one
- R
- Q, the heaviest one
- They are the same
Milo says a book on a high shelf has no energy because it isn't moving. Agree or disagree?
- Agree: it gets energy once thrown
- Agree: energy needs motion
- Disagree: it stores energy from its height
- Disagree: books make heat
Noah throws a ball straight up. A friend says it stores the most energy just as it leaves the hand, where it is fastest. Agree or disagree?
- Disagree: it stores the most at the top
- Agree: fastest means the most stored
- Disagree: nothing is stored while moving
- Agree: the hand gives it stored energy
Ren rolls a skateboard on a U-shaped ramp. It reaches a little lower on the other side. Where did the missing 10 J go?
- To thermal energy and sound
- Into more stored energy
- It was used up and is gone
- It stayed as motion energy at the top
Use this
Energy bar chart (example data), one bar per energy store, height in J. Ball held at 1 m: stored 5 J; thermal and sound 0 J. Top of the first bounce: stored 3 J; thermal and sound ?. A transfer arrow goes from motion to thermal and sound, labeled bounce.
Tala drops a ball; it bounces back lower. How much energy went to thermal energy and sound?
- 2 J
- 3 J
- 8 J
- 0 J; 2 J was destroyed
Zee lets a swing go and waits until it stops. What happened to the 300 J?
- It is still stored in the swing
- It turned back into the push
- It ran out and is gone
- It became 300 J of thermal energy