Question 3

A 250 N force is applied on a block of mass 25 kg. The 25 kg block is connected to a 10 kg block by a light inextensible string through a frictionless pulley as shown on the diagram below. The 250 N force acts at an angle of 25 o to the horizontal so that the system of blocks accelerates to the left. The coefficient of kinetic frictional force between the 25 kg block and the surface is 0,15.

3.1 Define the term kinetic frictional force. (2)

3.2 Draw a labelled free-body diagram of all forces acting on the 25 kg block. (5)

3.3 Calculate the:

3.3.1 Normal force exerted by the surface on the 25 kg block (3)

3.3.2 Acceleration of the system of blocks (7)

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