A force of 1N is required to stretch a spring by 1.5cm. If the spring is cut into three equal parts, find the force required to stretch one part by 3 cm.

Explanation

Spring constant `K=(F)/(x)=(1)/(1.5)N//cm.`Let k be the spring constant of each of the three parts into which the spring is cut, then
`(1)/(K)=(1)/(k)+(1)/(k)+(1)/(k)=(3)/(k)`
or `k=3K=3xx(1)/(1.5)=2N//cm.`
Force required, `F=kx^(')=2xx3=6N`