A roller-coaster car of mass 200 kg, with the engine switched off, travels along

track **ABC** which has a rough surface, as shown in the diagram below. At point **A**,

which is 10 m above the ground, the speed of the car is 4 m·s^{-1}.

At point **B**, which is at a height h above the ground, the speed of the car is 2 m·s^{-1}.

During the motion from point **A** to point **B**, 3,40 × 10^{3} J of energy is used to overcome

friction.

Ignore rotational effects due to the wheels of the car

5.1 Define the term *non-conservative force*. (2)

5.2 Calculate the change in the kinetic energy of the car after it has travelled from

point **A** to point **B**. (3)

5.3 Use energy principles to calculate the height *h*. (4)

On reaching point **B**, the car’s engine is switched on in order to move up the incline to

point **C**, which is 22 m above the ground. While moving from point **B** to point **C**, the car

travels for 15 s at a constant speed of 2 m·s^{-1}, while an average frictional force of 50 N

acts on it.

5.4 Calculate the power delivered by the engine to move the car from point B to

point **C**. (5)

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