1.Easy
A 4 kg block slides at 5 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 = 4 kgv = 5 m/sk = 400 N/m
x = cm
Work & energy worksheet with answers
2.Easy
A hoist lifts a 500 kg load at constant speed through a height of 3 m in 8 s. Find the average power P it delivers to the load, in kW.
m = 500 kgh = 3 mt = 8 sg = 9.81 m/s²
P = kW
3.Medium
A car travelling at 110 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 = 110 km/hμ = 0.8g = 9.81 m/s²
d = m
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 0.8. Find the stopping distance d.
v = 100 km/hμ = 0.8g = 9.81 m/s²
d = m
5.Hard
A 10 kg block is released from rest at height 1.5 m on a smooth ramp. At the bottom it crosses a rough horizontal strip 3.5 m long (μ = 0.2) and then runs onto a spring (k = 500 N/m) on a smooth surface. Find the maximum compression x of the spring.
m = 10 kgh = 1.5 mL = 3.5 mμ = 0.2k = 500 N/mg = 9.81 m/s²
x = cm
6.Hard
A 4 kg block is released from rest at height 3.5 m on a smooth ramp. At the bottom it crosses a rough horizontal strip 1 m long (μ = 0.3) and then runs onto a spring (k = 1000 N/m) on a smooth surface. Find the maximum compression x of the spring.
m = 4 kgh = 3.5 mL = 1 mμ = 0.3k = 1000 N/mg = 9.81 m/s²
x = cm
Answer key
- 1. x = 50 cm
- 2. P = 1.839 kW
- 3. d = 59.48 m
- 4. d = 49.16 m
- 5. x = 56.03 cm
- 6. x = 50.11 cm
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