Calculate kinetic and potential energy
Grade 11 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Ari watches a 2 kg toy cart speed up from 3 m/s to 5 m/s. How much kinetic energy does it gain?
Esme watches a 4 kg toy cart speed up from 1.5 m/s to 3.5 m/s. How much kinetic energy does it gain?
Jun reads the energy bar chart. How high above the floor is the ball? Use g = 9.8 m/s².
- 1 m: 9.8 J ÷ 9.8 m/s², leaving out the mass
- 2 m: 9.8 J ÷ (0.5 kg × 9.8 m/s²)
- 0.8 m: 4 J ÷ (0.5 kg × 9.8 m/s²), from the kinetic bar
- 19.6 m: 9.8 J ÷ 0.5 kg, leaving out g
Kira reads the energy bar chart. How fast is the ball moving?
Use the picture in question 3.
- 2.8 m/s: the root of 4 J ÷ 0.5 kg, leaving out the 2
- 4 m/s: v² = 2 × 4 J ÷ 0.5 kg = 16
- 8 m/s: the kinetic energy divided by the mass
- 16 m/s: the value of v², not rooted
Luz lifts the ball 1 m higher without changing its speed. Which bar changes, and by how much?
Use the picture in question 3.
- Both gravitational and kinetic, each up by 4.9 J
- Gravitational, up by 9.8 J: 1 m times g, leaving out the mass
- Gravitational, up by 0.5 J: the mass times 1 m, leaving out g
- Gravitational, up by 4.9 J; kinetic stays at 4 J
A drone holds a 2 kg box 12 m above the floor, then lifts it to 15 m. By how much does the box's gravitational energy grow? Use g = 9.8 m/s². Milo checks.
- 58.8 J: 2 × 9.8 × 3
- 6 J: 2 × 3, leaving out g
- 235.2 J: 2 × 9.8 × 12, using the starting height
- 294 J: 2 × 9.8 × 15, using the final height
Noah takes a table top, 0.7 m up, as zero height. A 3 kg box sits on a shelf 2.2 m above the floor. What is its gravitational energy? Use g = 9.8 m/s².
- 20.6 J: 3 × 9.8 × 0.7, the height of the table
- 4.5 J: 3 × 1.5, leaving out g
- 64.7 J: 3 × 9.8 × 2.2, measured from the floor
- 44.1 J: 3 × 9.8 × 1.5
A spring launcher has a spring constant of 300 N/m and is squeezed 0.20 m. How much energy does the spring store, Pia?
- 12 J: 300 × 0.20², leaving out the ½
- 6 J: ½ × 300 × 0.20²
- 30 J: ½ × 300 × 0.20, not squaring the squeeze
- 60 J: 300 × 0.20
A cart's mass triples while its speed is cut to half. What happens to its kinetic energy, Ren?
- It stays the same, because tripling and halving cancel
- It rises to 1.5 times its old value
- It falls to three quarters of its old value
- It falls to one sixth of its old value
A spring is swapped for one twice as stiff, and the squeeze is cut to half. What happens to the stored energy, Zee?
- It stays the same, because doubling and halving cancel
- It falls to one quarter, from the smaller squeeze alone
- It falls to half
- It rises to twice as much, from the stiffer spring alone