A 1 kg block slides at 6 m/s on a smooth horizontal surface into a spring of stiffness 800 N/m. Find the maximum compression x of the spring, in cm.
Work & energy worksheet with answers
A small ball hangs on a light string of length 1.5 m. It is pulled aside until the string makes 45° with the vertical and released from rest. Ignoring air resistance, find its speed v at the lowest point.
A block slides from rest down a slope at 45° to the horizontal. The coefficient of kinetic friction is 0.2. Find its speed v after it has slid 14 m along the slope.
A 10 kg block slides 5 m down a slope at 20° to the horizontal, with a coefficient of kinetic friction of 0.15. Find the work Wf done against friction.
A 4 kg block is released from rest at height 3 m on a smooth ramp. At the bottom it crosses a rough horizontal strip 2 m long (μ = 0.3) and then runs onto a spring (k = 4000 N/m) on a smooth surface. Find the speed v of the block when it reaches the spring.
A 5 kg block rests on a rough horizontal table (μ = 0.3). A light string runs from it over a smooth pulley at the edge of the table to a hanging 2 kg block. The system is released from rest. Find the speed v of the blocks after the hanging block has dropped 2.5 m.
Answer key
- 1. x = 21.21 cm
- 2. v = 2.936 m/s
- 3. v = 12.47 m/s
- 4. Wf = 69.14 J
- 5. v = 6.862 m/s
- 6. v = 1.872 m/s
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