In the figure, the ball A is released from rest when the spring is at its natural (unstretched) length. For the block B of mass M to leave contact with the ground at some stage, the minimum mass of A must be

Question

In the figure, the ball A is released from rest when the spring is at its natural (unstretched) length. For the block B of mass M to leave contact with the ground at some stage, the minimum mass of A must be <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-31pwqetd9mzm.png" /> (A) 2M (B) M (C) (M/2) (D) (M/4)

Tardigrade Admin · Accepted Answer

The spring will exert maximum force when the ball is at its lowest position. If the ball has descended through a distance

x

to reach the position.

mgx = (\frac{1}{2}) K x^{2}

or

x = \frac{2 m g}{k} \dots .

.....(i)
For block

B

to leave contact spring force,

K x = M g

.....(i)
Comparing equations (i) and (ii),

m = \frac{M}{2}

Q. In the figure, the ball $A$ is released from rest when the spring is at its natural (unstretched) length. For the block $B$ of mass $M$ to leave contact with the ground at some stage, the minimum mass of $A$ must be

$2 M$

$M$

$\frac{M}{2}$

$\frac{M}{4}$

Q. In the figure, the ball A is released from rest when the spring is at its natural (unstretched) length. For the block B of mass M to leave contact with the ground at some stage, the minimum mass of A must be

2M

M

2M​

4M​

The spring will exert maximum force when the ball is at its lowest position. If the ball has descended through a distance x to reach the position. mgx=(21​)Kx2 or x=k2mg​…. .....(i) For block B to leave contact spring force, Kx=Mg .....(i) Comparing equations (i) and (ii), m=2M​

Q. In the figure, the ball $A$ is released from rest when the spring is at its natural (unstretched) length. For the block $B$ of mass $M$ to leave contact with the ground at some stage, the minimum mass of $A$ must be

$2 M$

$M$

$\frac{M}{2}$

$\frac{M}{4}$