Question

A spring when compressed by 4 cm has 2 J energy stored in it. The force required
to extend it by 8 cm will be
20 N
2) 2 N
3) 200 N
4) 2000 N
The elastic potential energy of a stretched spring is given by E = 50x where x is​

Answer 1

Explanation:

Energy of spring = 1 / 2kx^2

Energy of spring = 1 / 2kx^22 = 1/2 ×k(4)^2×1/10^4

1/2 ×k(4)^2×1/10^4⇒1 × 10^4/ 4 = k

Force = kx = 1/4 × 8 ×10^2 = 200 N