Please use exact values throughout hence why I wrote u = 14.83...
So I drew this rough diagram to show you what's happening. In order to find the time, you need to find the new velocity after the stone S rebounds from the wall. Use the impulse equation to find this out.
Then use F = ma to calculate the new acceleration, remember the only force acting on the stone S is resistance acting in the opposite direction. You'll get the same acceleration as the initial acceleration because the resistance to motion hasn't changed but in the exam you may have a rough surface so your acceleration will be different than before. In this case, it is assumed to be smooth as the stone moves on ice.
You now have u (which is v in the diagram which is velocity the particle after it rebounds), acceleration, v' = 0 as it comes to rest and you need to find t.
I got t = 3.1 seconds as an answer to 2 significant figures.
Please use exact values throughout hence why I wrote u = 14.83...
So I drew this rough diagram to show you what's happening. In order to find the time, you need to find the new velocity after the stone S rebounds from the wall. Use the impulse equation to find this out.
Then use F = ma to calculate the new acceleration, remember the only force acting on the stone S is resistance acting in the opposite direction. You'll get the same acceleration as the initial acceleration because the resistance to motion hasn't changed but in the exam you may have a rough surface so your acceleration will be different than before. In this case, it is assumed to be smooth as the stone moves on ice.
You now have u (which is v in the diagram which is velocity the particle after it rebounds), acceleration, v' = 0 as it comes to rest and you need to find t.
I got t = 3.1 seconds as an answer to 2 significant figures.