- #1

- 5

- 0

## Homework Statement

A particle moves in the x-y plane relative to a fixed point O. Initially, the particle is at the point 6i-2j, where I and J are position vectors in the directions of the x and y axis respectively. The particle moves such that t seconds after the start of its moition, the velocity of the particle is given by 3cos(3t)i - 2sin(6t)j. Find an expression in terms of t for:

a) acceleration of particle

b) its displacement

[Hint: Use radiains]

## Homework Equations

a) Chain rule for differenting dy/dx = dt/dx * dt/dx the function 3cos(3t)i - 2sin(6t)j

b) Integration of function 3cos(3t)i - 2sin(6t)j

## The Attempt at a Solution

a) -9sin(3t)i - 12cos(6t)j

b) sin(3t)i + 1/3cos(6t)j + c.

**Further**

I don't really get ijk notation or how to use it effectively. I know how to switch from polar to component form for simple equations, but with trigonometric functions I'm getting really confused. I have no idea if what I'm doing is correct for this. I'm assuming 6i-2j is its displacement, but I'm not sure what to do with it. I know t= d/v, but that's about it. Any hints/resources to help me get around using ijk in mechanics based questions would be great.

Edit: I realised that if t=0, then s = 6i-2j. So to solve for c, 6i-2j = sin(3t)i + 1/3cos(6t)j + c. But aye, any useful redirects to worthwhile resources on ijk stuff would be great.

Last edited: