JEE Main 18 March 2021 Shift 2 Solved Paper

Given, mass of the ball, m=4kg
Velocity of the ball, v=10m/s
Force constant, k=100N/m
The length of the spring, x=8m
Let x is the compressed length of the spring.
Using the work-energy theorem,
"It states that kinetic energy of the ball is converted into the stored energy of spring".
‌

mv2

2

=‌

kx2

2

⇒‌‌‌

4(10)2

2

=‌

(100)x2

2

⇒x=2m
The final length (compressed) of the spring
=8−2=6m
Hence, the value of x to the nearest integer is 6 .