1.Easy
A crate is pulled 17 m along a level floor by a rope that makes 45° with the horizontal. The tension in the rope is 120 N. Find the work W done by the rope on the crate.
F = 120 Nd = 17 mθ = 45°
W = J
Work & energy worksheet with answers
2.Easy
A crate is pulled 18 m along a level floor by a rope that makes 30° with the horizontal. The tension in the rope is 70 N. Find the work W done by the rope on the crate.
F = 70 Nd = 18 mθ = 30°
W = J
3.Medium
A 5 kg block slides 12 m down a slope at 40° to the horizontal, with a coefficient of kinetic friction of 0.25. Find the work Wf done against friction.
m = 5 kgθ = 40°μ = 0.25d = 12 mg = 9.81 m/s²
Wf = J
4.Medium
A block slides from rest down a slope at 40° to the horizontal. The coefficient of kinetic friction is 0.2. Find its speed v after it has slid 4 m along the slope.
θ = 40°μ = 0.2d = 4 mg = 9.81 m/s²
v = m/s
5.Hard
A 2.5 kg block is released from rest at height 3 m on a smooth ramp. At the bottom it crosses a rough horizontal strip 4.5 m long (μ = 0.3) and then runs onto a spring (k = 5000 N/m) on a smooth surface. Find the maximum compression x of the spring.
m = 2.5 kgh = 3 mL = 4.5 mμ = 0.3k = 5000 N/mg = 9.81 m/s²
x = cm
6.Hard
A 0.5 kg cart is released from rest at a height of 8 m on a smooth track that leads into a vertical circular loop of radius 2.5 m. Find the normal force N the track exerts on the cart at the top of the loop.
m = 0.5 kgh = 8 mR = 2.5 mg = 9.81 m/s²
N = N
Answer key
- 1. W = 1442 J
- 2. W = 1091 J
- 3. Wf = 112.7 J
- 4. v = 6.199 m/s
- 5. x = 12.72 cm
- 6. N = 6.867 N
Full step-by-step solutions: practise this topic on examproblems.com.