1.Easy
A crate is pulled 14 m along a level floor by a rope that makes 40° with the horizontal. The tension in the rope is 40 N. Find the work W done by the rope on the crate.
F = 40 Nd = 14 mθ = 40°
W = J
Work & energy worksheet with answers
2.Easy
A 2 kg block slides at 3.5 m/s on a smooth horizontal surface into a spring of stiffness 2000 N/m. Find the maximum compression x of the spring, in cm.
m = 2 kgv = 3.5 m/sk = 2000 N/m
x = cm
3.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 0.8. Find the stopping distance d.
v = 100 km/hμ = 0.8g = 9.81 m/s²
d = m
4.Medium
A block slides from rest down a slope at 25° to the horizontal. The coefficient of kinetic friction is 0.3. Find its speed v after it has slid 16 m along the slope.
θ = 25°μ = 0.3d = 16 mg = 9.81 m/s²
v = m/s
5.Hard
A 5 kg cart is released from rest at a height of 3.9 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 = 5 kgh = 3.9 mR = 1.5 mg = 9.81 m/s²
N = N
6.Hard
A 2 kg cart is released from rest at a height of 13 m on a smooth track that leads into a vertical circular loop of radius 5 m. Find the normal force N the track exerts on the cart at the top of the loop.
m = 2 kgh = 13 mR = 5 mg = 9.81 m/s²
N = N
Answer key
- 1. W = 429 J
- 2. x = 11.07 cm
- 3. d = 49.16 m
- 4. v = 6.879 m/s
- 5. N = 9.81 N
- 6. N = 3.924 N
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