After the salmon has re-entered the river, it has lost nearly all its original kinetic energy. State what has happened to the lost energy.

Another salmon, of much greater mass, leaves the water vertically with the same speed. State and explain how the height of this salmon's jump compares to the height reached by the first salmon.

Calculate the speed of the car at A.

As the car travels from A to B, it loses 40kJ of energy due to friction. The car just manages to roll over the crest of the hill at B. Calculate height h.

At C, the car is slowed down by a shallow tank of water and the kinetic energy of the car is reduced to zero. Make 3 suggestions for what happens to this kinetic energy.

Calculate the useful work done in lifting the crate.

(a) Calculate the kinetic energy of the aircraft at take-off.

(b) On an aircraft carrier, a catapult provides an accelerating force on the aircraft. The catapult provides a constant force for a distance of 150m along the deck. Calculate the resultant force on the aircraft as it accelerates. Assume that all of the kinetic energy at take off is from the work done on the aircraft by the catapult.

(a) Calculate the increase in the total gravitational potential energy (gpe) of the passangers.

(b) The engine of the train has a power of 1500kW. The time taken to reach the top of the mountain is 30 minutes.