Work & energy worksheet with answers

A crate is pulled 7 m along a level floor by a rope that makes 40° with the horizontal. The tension in the rope is 110 N. Find the work W done by the rope on the crate.

A small ball hangs on a light string of length 2 m. It is pulled aside until the string makes 50° with the vertical and released from rest. Ignoring air resistance, find its speed v at the lowest point.

A 0.5 kg ball hangs on a light string of length 0.8 m. It is pulled aside until the string makes 40° with the vertical and released from rest. Find the tension T in the string when the ball passes the lowest point.

A 1 kg block slides 18 m down a slope at 40° to the horizontal, with a coefficient of kinetic friction of 0.2. Find the work W_f done against friction.

An 8 kg block rests on a rough horizontal table (μ = 0.4). A light string runs from it over a smooth pulley at the edge of the table to a hanging 6 kg block. The system is released from rest. Find the speed v of the blocks after the hanging block has dropped 2 m.

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 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.