Question

A mass of 2 kg falls from a height of 40cm on a spring of for force constant 1960n/m.the spring is compressed by?

Answer 1

Suppose h is the height from which the

 mass m falls on the spring of force

 constant K and x is the compression in

 the spring.

The

Gain in elastic potential energy of spring

=Loss in gravitational potential energy of

 falling mass

or

1

2

Kx

2

=mg (h+x)

1

2

×1960×

x

2

=2×9.8 (0.40 +x)

On solving we get

 x=10cm