Question

A boy determines the greatest strength of his hands by means of a forcématėsi. Find the work done by him, if the force shown by the forcemeter is 600 N. The coefficient of elasticity of the forcemeter system is k = 10 000 N / m.

Answer 1

$W=\frac{kx^2}{2}$

$F=kx\to x=F/k$

So, we have

$W=\frac{k\cdot F^2}{2\cdot k^2}=\frac{F^2}{2k}=\frac{600^2}{2\cdot10000}=18\ (J)$ . Answer