Question

A spring with spring constant 300 N/m hangs from the ceiling. James Bond attaches a block of mass 0.5 kg to the unstretched spring and releases it from rest.

A) How far below the starting point does the block fall before coming momentarily to rest?

B) What is the maximum speed the block will reach as it falls?

Answer 1

(A) The expression for the spring force is, F = kx The expression for the weight of the block is, F = mg Equate both the forces as follows: mg = kx mg (0.5 kg)(9.8 m/s) (300 N/m = 0.0163 m =1.63 cm The distance of the block falls before coming to momentarily rest is, d = 2x = 2(1.63 cm) = 3.26 cm (B) The expression for the maximum speed of the block is, Umax = 40 = (1.63x10-2 m) 300 N/m 10.5 kg300 = 39.92 cm