Question 1

Paper 2Medium4 marks

A block is attached to a fixed support by a stretched horizontal spring and rests on a rough horizontal table. It remains at rest, and no other horizontal forces act on it. Figure 1 gives the block’s mass and the spring’s constant and extension. Use g=9.81 m s−2g=9.81\ \mathrm{m\,s^{-2}}

k=120 N m-1extension x=0.080 mm=2.0 kg
(a)

Calculate the magnitude of the force exerted by the spring on the block.

[1]
(b)

Determine the minimum coefficient of static friction between the block and the table for the block to remain at rest.

[3]

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