A car of mass \(2000\text{ kg}\) travels in a straight line on a horizontal road. The car accelerates from \(10\text{ m s}^{-1}\) to \(20\text{ m s}^{-1}\) in \(8\text{ s}\). Assume that resistance can be ignored.

Use the work-energy principle to find the work done by the driving force.

Enter just the number in joules.

A car of mass \(2000\text{ kg}\) accelerates from \(10\text{ m s}^{-1}\) to \(20\text{ m s}^{-1}\) in \(8\text{ s}\) on a horizontal road. Resistance can be ignored.

Find the average power generated by the engine.

Enter just the number in kW.

The engine of a \(5\text{ tonne}\) truck has a power output of \(400\text{ kW}\). The truck is travelling in a straight line on a horizontal road. The resistance to motion is \(20000\text{ N}\).

Find the maximum speed the truck could achieve.

Enter just the number.

The maximum power of a boat engine is \(140\text{ kW}\). The boat is subject to a resistance force of \(10000\text{ N}\).

Find the maximum speed the boat can achieve when travelling in a straight line.

Enter just the number.

A model train of mass \(200\text{ g}\) is moving in a straight line on a level track. The train accelerates from \(2\text{ m s}^{-1}\) to \(8\text{ m s}^{-1}\) in \(3\text{ s}\).

Find the average power generated by the engine.

Enter just the number in watts.