Calculate kinetic and potential energy
Grade 11 Science Worksheet
Circle the best answer, or write your answer on the line.
Ari launches a 0.2 kg ball straight up at 7 m/s. Ignoring air, how high above the launch point does it rise? Use g = 9.8 m/s².
Bo launches a 0.5 kg ball straight up at 14 m/s. Ignoring air, how high above the launch point does it rise? Use g = 9.8 m/s².
Esme launches a 3 kg ball straight up at 4.2 m/s. Ignoring air, how high above the launch point does it rise? Use g = 9.8 m/s².
A 2 kg cart rolls 4.0 m down a ramp that drops 1.5 m and reaches the bottom at 3.0 m/s. Using g = 9.8 m/s², what is the average friction force, Jun?
- 5.1 N: (29.4 J − 9 J) ÷ 4.0 m
- 2.25 N: 9 J ÷ 4.0 m, from the motion alone
- 7.35 N: 29.4 J ÷ 4.0 m, from the drop alone
- 13.6 N: (29.4 J − 9 J) ÷ 1.5 m, over the drop
A ball starts at rest 2.0 m up and ends 0.5 m up, with no friction. Path A is a straight ramp; path B dips to the floor first. Compare the paths, Kira.
- Same end speed, 6.3 m/s, as both start 2.0 m up
- Path A ends faster, because its shorter route wastes less energy
- Path B ends faster, because it dips lower and gains more speed
- Same end speed, 5.4 m/s; path B reaches 6.3 m/s at its dip
A motor lifts a 5 kg box 3.0 m in 4.0 s while taking 200 J of electrical energy. Using g = 9.8 m/s², what are the useful power and efficiency, Luz?
- 36.75 W useful, 73.5% efficient
- 36.75 W useful, 26.5% efficient
- 147 W useful, 73.5% efficient
- 50 W useful, 73.5% efficient
A 5 kg box rises from a shelf 1.5 m up to a hook 2.1 m up. Milo measures height from the floor; a friend uses a table top 0.9 m up. Results?
- Their gains differ by 44.1 J, the table's share of height
- Both find a gain of 29.4 J, though their totals differ
- Neither can find a gain, because their totals disagree
- The floor reading gives a gain of 102.9 J and the table reading 29.4 J
A 0.5 kg ball floats 3 m above the ground over a pit 2 m deep. Using g = 9.8 m/s², what is its gravitational energy measured from the pit floor, Noah?
- 24.5 J: 0.5 × 9.8 × 5
- 14.7 J: measured from the ground
- 4.9 J: 0.5 × 9.8 × 1, from 3 − 2
- 9.8 J: 0.5 × 9.8 × 2, the depth of the pit
A 4 kg cart rolls on a level track at 6.0 m/s and slows to 4.0 m/s over 5.0 m. With steady friction, how much farther does Ren's cart roll before it stops?
- 5.0 m: the same distance as the first stretch
- 4.0 m: 40 J ÷ 5.0 m = 8 N, then 32 J ÷ 8 N
- 8.0 m: 32 J ÷ 4 N, taking friction as 4 N
- 9.0 m: 72 J ÷ 8 N, the whole stop from 6 m/s
A 0.80 kg block slides 1.5 m down a smooth ramp that drops 0.90 m, then squeezes a 980 N/m spring on a smooth floor. How far is the spring squeezed, Zee?
- 0.085 m: 980 × x² = 0.80 × 9.8 × 0.90
- 0.155 m: ½ × 980 × x² = 0.80 × 9.8 × 1.5
- 0.007 m: 980 × x = 0.80 × 9.8 × 0.90
- 0.12 m: ½ × 980 × x² = 0.80 × 9.8 × 0.90