A 1 kg ball is dropped from rest from a height of 36 m. Ignore air resistance. Find its speed v just before it hits the ground.
Work & energy worksheet with answers
A crate is pulled 18 m along a level floor by a rope that makes 45° with the horizontal. The tension in the rope is 90 N. Find the work W done by the rope on the crate.
A toy launcher has a vertical spring of stiffness 1500 N/m. A 0.1 kg ball is placed on it and the spring is compressed by 10 cm, then released. Ignoring air resistance and the spring’s mass, find the height h the ball rises, measured from its position when the spring was compressed.
A 0.5 kg block slides 10 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.
A 5 kg cart is released from rest at a height of 5.3 m on a smooth track that leads into a vertical circular loop of radius 1.5 m. Find the speed v of the cart at the top of the loop.
A 2 kg block starts from rest at the bottom of a 35° slope and is pulled up the slope by a constant force of 35 N parallel to the slope. The coefficient of kinetic friction is 0.3. Find the speed v of the block after it has moved 5 m up the slope.
Answer key
- 1. v = 26.58 m/s
- 2. W = 1146 J
- 3. h = 7.645 m
- 4. Wf = 9.394 J
- 5. v = 6.718 m/s
- 6. v = 9.728 m/s
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