1.Easy
A 0.5 kg block slides at 4 m/s on a smooth horizontal surface into a spring of stiffness 400 N/m. Find the maximum compression x of the spring, in cm.
m = 0.5 kgv = 4 m/sk = 400 N/m
x = cm
Work & energy worksheet with answers
2.Easy
A crate is pulled 5 m along a level floor by a rope that makes 45° with the horizontal. The tension in the rope is 160 N. Find the work W done by the rope on the crate.
F = 160 Nd = 5 mθ = 45°
W = J
3.Medium
A 5 kg block slides 13 m down a slope at 35° to the horizontal, with a coefficient of kinetic friction of 0.25. Find the work Wf done against friction.
m = 5 kgθ = 35°μ = 0.25d = 13 mg = 9.81 m/s²
Wf = J
4.Medium
A car travelling at 100 km/h on a level road brakes hard and skids to a stop with its wheels locked. The coefficient of kinetic friction between the tyres and the road is 0.5. Find the stopping distance d.
v = 100 km/hμ = 0.5g = 9.81 m/s²
d = m
5.Hard
A 3 kg block rests on a rough horizontal table (μ = 0.1). A light string runs from it over a smooth pulley at the edge of the table to a hanging 4 kg block. The system is released from rest. Find the speed v of the blocks after the hanging block has dropped 2 m.
m1 = 3 kgm2 = 4 kgμ = 0.1d = 2 mg = 9.81 m/s²
v = m/s
6.Hard
A 0.5 kg cart is released from rest at a height of 6 m on a smooth track that leads into a vertical circular loop of radius 1.5 m. Find the normal force N the track exerts on the cart at the top of the loop.
m = 0.5 kgh = 6 mR = 1.5 mg = 9.81 m/s²
N = N
Answer key
- 1. x = 14.14 cm
- 2. W = 565.7 J
- 3. Wf = 130.6 J
- 4. d = 78.65 m
- 5. v = 4.554 m/s
- 6. N = 14.71 N
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