A Level Maths mechanics help (vectors)

can someone please help me with part b the answer is t=10 and c=10 but i dont know how to get there. i have tried r = ut + 1/2at^2 but im not getting that answer

Reply 1

lee_miller7

Original post by lee_miller7

can someone please help me with part b the answer is t=10 and c=10 but i dont know how to get there. i have tried r = ut + 1/2at^2 but im not getting that answer

Reply 2

mqb2766

Original post by lee_miller7

It helps to see what you did, but remember A will have an initial position/displalcement offfset of 44 (for the ith component) which youve not written in the suvat. Or translate the origin to A.

(edited 1 month ago)

Reply 3

lee_miller7

Original post by mqb2766

It helps to see what you did, but remember A will have an initial position/displalcement offfset of 44 (for the ith component) which youve not written in the suvat. Or translate the origin to A.

could you expand on this more. i dont know what i am meant to do with the displacement of A

Reply 4

mqb2766

Original post by lee_miller7

could you expand on this more. i dont know what i am meant to do with the displacement of A

The usual suvat assumes that the displacement is 0 at t=0 as there is no initial "s0" in the suvat equation. Here your initial position is A so in the ith component you have
s = 44 + ut + 1/2at^2
to get the position / displacement from the origin.

Or use the usual suvat and translate the origin to A so the new position of C is
AC = OC - OA = ...

(edited 1 month ago)