A constant force, F, pulls a 50 kg block at a constant speed over a rough horizontal
surface, AB, as shown in the diagram below. The coefficient of kinetic friction (μk)
between the block and the surface is 0,4.

3.1 Draw a labelled free-body diagram showing ALL the forces acting on the
block. (4)
3.2 State Newton’s first law of motion in words. (2)
Calculate the magnitude of the:
3.3 Force F (2)
3.4 Normal force (2)
3.5 Frictional force (2)
The same constant force, F, is now applied to the block over the same rough horizontal
surface as before, but in the direction shown below.

3.6 Give a reason why the block will move slower than before. (2)
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