Assessment: Work and Energy

A weightlifter holds a barbell perfectly still above their head for 10 seconds. How much work do they do on the barbell during this time?

Find the kinetic energy of a 0.5 kg ball moving at 10 m/s.

A pump does 12,000 J of work in 3 minutes. Find its power. (Round to the nearest whole number.)

Find the GPE of a 20 kg object at a height of 8 m (g = 9.8 m/s²).

A spring with spring constant 300 N/m is compressed by 0.08 m. Find the elastic potential energy stored.

A pendulum bob of mass 0.3 kg swings down from a height of 0.2 m above its lowest point. Ignoring air resistance, find its speed at the lowest point (g = 9.8 m/s²). (Round to 2 decimal places.)

A tow truck pulls a broken-down car with a force of 2000 N over a distance of 15 m. Find the work done.

A 900 kg car's speed increases from 10 m/s to 20 m/s. Find the increase in its kinetic energy.

A 2 kg block slides from rest down a frictionless ramp, dropping a height of 1.5 m, then slides onto a rough horizontal surface where friction brings it to rest after 3 m. Find the average friction force (g = 9.8 m/s²).

A crane lifts a 500 kg load a height of 6 m in 4 s. Find the power required (g = 9.8 m/s²).