Question

If a man of mass M jumps to the ground from a height h and his centre of mass moves a distance of x during the impact, the average force acting on him (assuming his retardation to be constant during his impact with the ground) is

• A. $\frac{Mgh}{x}$
• B. $\frac{Mgx}{h}$
• C. $Mg{\left(\frac{h}{x}\right)}^2$
• D. $Mg{\left(\frac{x}{h}\right)}^2$

Answer 1

The correct option is A

$\frac{Mgh}{x}$

Since the centre of mass moves through a distance x, the average force $F$ is given by $Fx=Mgh$
$\Rightarrow F=\frac{Mgh}{x}$
Hence, the correct choice is (a).