An object of mass 1,8 kg slides down a rough curved track and passes point **A**, which is 1,5 m above the ground, at a speed of 0,95 m·s^{-1}.

The object reaches point **B** at the bottom of the track at a speed of 4 m·s^{-1}.

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

5.2 Name the conservative force acting on the object. (1)

5.3 Is mechanical energy conserved as the object slides from point **A** to point **B**? Choose from YES or NO.

Give a reason for the answer. (2)

5.4 Calculate the gravitational potential energy of the object when it was at point **A**. (3)

5.5 Using energy principles, calculate the work done by friction on the object as it slides from point **A** to point **B**. (4)

Surface **BC** in the diagram above is frictionless.

5.6 What is the value of the net work done on the object as it slides from point **B** to point **C**? (1)

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