Originally Posted by

**craig** Got a question involving power, but not sure how to start it.

Lorry of weight $\displaystyle W$ generates power $\displaystyle P$. The lorry has max. speed of $\displaystyle \mu$ on a level road, but $\displaystyle v < \mu$ on a slope inclined at angle $\displaystyle \alpha$ to the horizontal.

If the power and resistance of the lorry stay the same and are constant, show that:

$\displaystyle \mu vW \sin{\alpha} = P(\mu - v)$

Guessing this involves resolving the forces, not sure where to start though.

Thanks in advance