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# Vectors in M1 watch

1. Hi, stuck on a question so just wondering if anyone could help, please. I've answered a) and b) but it's specifically part c) that I'm having trouble with.

A particle P of mass 5kg is moving under the action of a constant force F newtons. At t = 0, P had velocity (5i - 3j) m/s. At t = 4s, the velocity of P is (-11i + 5j) m/s. Find:

a) the acceleration of P in terms of i and j.
b) the magnitude of F.

At t = 6s, P is at the point A with position vector (28i + 6j) m relative to a fixed origin O. At this instant the force F newtons is removed and P then moves with constant velocity. Two seconds after the force has been removed, P is at the point B.

c) Calculate the distance of B from O.

a) a = (-4i + 2j) m/s^2
b) 22.4N
c) 26m
2. You need to ask: what is the velocity of P at t = 6? Say it's x. So when the forced is removed, this velocity x will continue for 2 more seconds, and then P will be at point B, which is easy to find using A and the velocity x. Once you have B in terms of i's and j's, you can find the distance by taking the magnitude of B's position vector.

Does that clarify it a bit?
3. (Original post by Dream Eater)
You need to ask: what is the velocity of P at t = 6? Say it's x. So when the forced is removed, this velocity x will continue for 2 more seconds, and then P will be at point B, which is easy to find using A and the velocity x. Once you have B in terms of i's and j's, you can find the distance by taking the magnitude of B's position vector.

Does that clarify it a bit?
Thanks so much for your help! Much appreciated. I've done it now.
4. can you go through it step by step please? ty

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