According to Hookes Law the force needed to stretch a spring

According to Hooke\'s Law, the force needed to stretch a spring is directly proportional to the amount the spring is stretched. If 30 pounds of force stretches a spring 3 inches, how much will the spring be stretched by a force of 69 pounds?

Solution

As per Hooke\'s Law : Force proportional stretch in spring i.e.

F = k(x)

where F = force ; x= stretch of spring and k = spring constant

So, F1 = 30 pounds , x1=3 inch , F2 = 69 pounds , x2 = ??

F2/F1 = x2/x1

69/30 = x2/3

x2 = 69/30*3 = 6.9 inches