In two different experiments, an object of mass 5 kg moving with a speed of 25 m s⁻¹ hits two different walls and comes to rest within (i) 3 second, (ii) 5 seconds, respectively. Choose the correct option out of the following.

Question

Accepted Answer

(2) Impulse will be same for the cases but the average force will be different.. Idea: impulse is fixed by the momentum change alone; the time only decides how that impulse is spread out as force. Both experiments take the same object from 25 m s⁻¹ to rest, so |J|=|Δ p|=mΔ v=5×25=125 N s in each case — the same. Average forces: F₁=(125)/3≈41.7 N, F₂=(125)/5=25 N — different. So the impulse is the same and the average force is not. This is the principle behind crumple zones and airbags: the impulse a crash must absorb is fixed, so the only way to cut the force is to stretch the time.

In two different experiments, an object of mass 5 kg moving with a speed of 25 m s⁻¹ hits two different walls and comes to rest within (i) 3 second, (ii) 5 seconds, respectively. Choose the correct option out of the following.

Step-by-step solution

Why the other options are wrong