(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

"A particle moves in the horizontal plane that contains the perpendicular unit vectorsiandj. Initially it is at the origin and has velocity 18ims^-1. After accelerating for 10 seconds its velocity is (30i+ 8j)ms^-1. Assume that the acceleration of the particle is constant.

a) Find the acceleration of the particle

b) Find the position vector of the particle when the velocity is (36i+ 12j)ms^-1.

2. The attempt at a solution

For (a) i managed to find out the acceleration being (1.2i+ 0.8j)ms^-2 using v=at+u and rearranging it to a=(v-u)/t.

But for (b) it says the answer is 405i+ 90j

I've tried it over and over again but I don't think the question was specific enough (probably just me not understanding it).

I've tried it this way using:

u=18i+ 0j

v=36i+ 12j

t=10

R (position vector; i used R=(t/2)(u+v))=5(u+v) which gives the vector R= 240i+ 40j

I've tried it by replacing the initial velocity with 36i+ 12jbut that didn't work either. I can probably work out the question if I understood what it basically is asking for.

Someone Please run me through this, I'm not good at mechanics :'(

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# Homework Help: Kinematics in 2 dimensions; position vector problem.

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