Question

24. A block of mass 'm' moving with a speed v compresses a spring through a distance 'x before its speed reduces by 25%. The spring constant of the spring is

1)mv²/4x²
2)3mv²/4x²
3)7mv²/16x²
4)9mv²/16x²​

Answer 1

Explanation:

From conservation of energy,

Loss in kinetic energy of block=Gain in potential energy of spring

⟹

2

1

mv

2

−

2

1

m(

2

v

)

2

=

2

1

kx

2

⟹

8

3mv

2

=

2

1

kx

2

⟹k=

4x

2

3mv

2