Question

A mass of 0.2 kg is attached to the lower end of a masseless spring of force constant 200 Nm^–1, the upper end of which is fixed to a rigid support. Which of the following statement is not true :–

(a) The frequency of oscillation will be nearly 5 Hz 

(b) In equilibrium, the spring will be stretched by 2cm 

(c) If the mass is raised till the spring is unstretched state and then released, it will go down by 2 cm before moving upward 

(d) If the system is taken to a planet, the frequency of oscillation will be the same as on the earth.

Answer 1

Correct option (b) In equilibrium, the spring will be stretched by 2cm 

Explanation:

In equilibrium, kx = mg

When mass is raised till the spring is unstretched, the work

= 1/2kx2 = mgx

When the mass is released from the unstretched position of spring,

As υ of spring is independent of g so that the frequency of oscillation will be the same as that on the earth.