- #1

- 365

- 0

## Homework Statement

A particle has a mass of 2kg and moves in the xy plane with a constant speed of 3m/s along the direction of the vector r = i + j. What is the particle's angular momentum relative to the point (0,5) meters?

## Homework Equations

L = rmv

L = mvrsin(theta)

## The Attempt at a Solution

I am studying for my exam and i am a little confused about this problem.

I know the answer is 21 kgm

^{2}/s

and the work to get that answer is (2kg)(3m/s)(5m)sin(45) = 21

So i get where the mass (2kg) and the velocity (3m/s) go in the equation but i dont get why the 5m is in there and how would i know to use the angle 45 degrees?

Thanks for any help on clarifying this up for me :)