Question

29. A block of mass M is connected to a massless pulley and massless spring of stiffness k The
pulley is frictionless. The spring connecting the block and spring is massless. Initially the spring
is unstretched when the block is released. When the spring is maximum stretched, then tension
(d) Mg/2
2mg
in the rope is
(a) zero
(b) Mg

Answer 1

Answer:

It will be Mg......

since the pulley is massless and spring is ideal in nature there fore only force of gravity would act on it.

hope it would be helpful

Answer 2

Answer:

The tension in the string when it is stretched to the maximum is 2mg.

Explanation:

Assuming the maximum stretch in the spring to be s.

Let us use the law of conservation of energy,

Potential Energy=Kinetic Energy

∴$mgs=\frac{1}{2}ks^{2}$

∴ks=2mg.   ...(1)

We know that,

Tension in the string=

T=ks.       ...(2)

From equations (1) and (2)

T=2mg

Therefore, the tension in the string when it is stretched to the maximum is 2mg.