1.Easy
A 4 kg block slides at 6 m/s on a smooth horizontal surface into a spring of stiffness 800 N/m. Find the maximum compression x of the spring, in cm.
m = 4 kgv = 6 m/sk = 800 N/m
x = cm
Work & energy worksheet with answers
2.Easy
A 1 kg ball is dropped from rest from a height of 22 m. Ignore air resistance. Find its speed v just before it hits the ground.
m = 1 kgh = 22 mg = 9.81 m/s²
v = m/s
3.Medium
A toy launcher has a vertical spring of stiffness 400 N/m. A 0.05 kg ball is placed on it and the spring is compressed by 6 cm, then released. Ignoring air resistance and the spring’s mass, find the height h the ball rises, measured from its position when the spring was compressed.
m = 0.05 kgk = 400 N/mx = 6 cmg = 9.81 m/s²
h = m
4.Medium
A toy launcher has a vertical spring of stiffness 2000 N/m. A 0.15 kg ball is placed on it and the spring is compressed by 2 cm, then released. Ignoring air resistance and the spring’s mass, find the height h the ball rises, measured from its position when the spring was compressed.
m = 0.15 kgk = 2000 N/mx = 2 cmg = 9.81 m/s²
h = m
5.Hard
A 15 kg block starts from rest at the bottom of a 20° slope and is pulled up the slope by a constant force of 145 N parallel to the slope. The coefficient of kinetic friction is 0.15. Find the speed v of the block after it has moved 7 m up the slope.
m = 15 kgF = 145 Nθ = 20°μ = 0.15d = 7 mg = 9.81 m/s²
v = m/s
6.Hard
A 20 kg block starts from rest at the bottom of a 35° slope and is pulled up the slope by a constant force of 210 N parallel to the slope. The coefficient of kinetic friction is 0.1. Find the speed v of the block after it has moved 5 m up the slope.
m = 20 kgF = 210 Nθ = 35°μ = 0.1d = 5 mg = 9.81 m/s²
v = m/s
Answer key
- 1. x = 42.43 cm
- 2. v = 20.78 m/s
- 3. h = 1.468 m
- 4. h = 0.2718 m
- 5. v = 8.307 m/s
- 6. v = 6.379 m/s
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