Question

An elephant and a mouse would both have zero weight in gravity-free space. If they were moving toward you with the same speed, would they bump into you with the same effect? Explain.

Answer 1

The elephant and the mouse having zero weight in a gravity free space will not bump into you at the same effect.

Explanation:

When both are in a gravity free space, the weights are zero, as we know that the$\text {weight of the body}=\text {mass of the body} \times \text {acceleration due to gravity}$

$\text {here, the weight of elephant}=\text {mass of elephant } \times \text {zero gravti} y=zero$

$\text {similarly,weight of mouse}=\text {mass of mouse } \times \text {zero gravity}=zero$

But when they will acquire the speed of same magnitude, say v, their different masses will acquire different momentum, which will make the difference in effect while bumping.  

$\text { momentum of elephant }=\text { mass of elephant } \times v$  $\text { momentum of mouse = mass of mouse } \times v$

And as we know $\text { mass of elephant }>\text { mass of mouse }$  Therefore, effect of impact by elephant will be more than that of mouse . An elephant breaking into you will take you back faster than a mouse in space hits you.