# Torque direction for any system of particles

## Homework Statement

A particle is to move in an xy plane, clockwise around the origin as seen from the positive side of the z axis. In unit-vector notation, what torque acts on the particle at time t = 9.5 s if the magnitude of its angular momentum about the origin is (a) 8.0 kg·m2/s, (b) 8.0t^2 kg·m2/s3, (c) 8.0t^(1/2) kg·m2/s3/2, and (d) 8.0/t^2 kg·m2*s?

τ=dL/dt

## The Attempt at a Solution

All i have to do is take the time derivative of the given angular momentum and plug in t. I can get the magnitude of the torque with the equation but i do not know how to get the direction of torque. Please explain! Thanks