Question

The potential energy stored in a spring is U when it is stretched for length 10 cm. If the spring is stretched for the next 10 cm then the change in its potential energy is equal to the:
a.3U
b.4U
c.2U
d.None of these

Answer 1

Answer:

Correct option is 4U

Explanation:

Correct option is B)

For 1st situation,

E=

2

1

k(10×10

−2

)

2

........ (i)

For 2nd situation,

E

′

=

2

1

k(20×10

−2

)

2

........ (ii)

On comparing Eqs. (i) and (ii), we get

E

′

=4E