1.Easy
A 5 kg block slides at 2 m/s on a smooth horizontal surface into a spring of stiffness 500 N/m. Find the maximum compression x of the spring, in cm.
m = 5 kgv = 2 m/sk = 500 N/m
x = cm
Work & energy worksheet with answers
2.Easy
A hoist lifts a 100 kg load at constant speed through a height of 12 m in 10 s. Find the average power P it delivers to the load, in kW.
m = 100 kgh = 12 mt = 10 sg = 9.81 m/s²
P = kW
3.Medium
A car travelling at 60 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 0.6. Find the stopping distance d.
v = 60 km/hμ = 0.6g = 9.81 m/s²
d = m
4.Medium
A 10 kg ball hangs on a light string of length 0.5 m. It is pulled aside until the string makes 20° with the vertical and released from rest. Find the tension T in the string when the ball passes the lowest point.
m = 10 kgL = 0.5 mθ = 20°g = 9.81 m/s²
T = N
5.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 1.5 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 = 4 kgh = 3.5 mL = 1.5 mμ = 0.2k = 500 N/mg = 9.81 m/s²
x = cm
6.Hard
A 2.5 kg block is released from rest at height 2.5 m on a smooth ramp. At the bottom it crosses a rough horizontal strip 1.5 m long (μ = 0.3) and then runs onto a spring (k = 800 N/m) on a smooth surface. Find the maximum compression x of the spring.
m = 2.5 kgh = 2.5 mL = 1.5 mμ = 0.3k = 800 N/mg = 9.81 m/s²
x = cm
Answer key
- 1. x = 20 cm
- 2. P = 1.177 kW
- 3. d = 23.6 m
- 4. T = 109.9 N
- 5. x = 70.87 cm
- 6. x = 35.45 cm
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