# Raising a block

1. Sep 27, 2011

### Expat09

This is more a question about how the problem is written, rather than a question about how to do the problem

Why do they ask for tan γ in terms of d/l and h/l, rather than d and h? Is there some relation that I'm just not seeing? I'm pretty sure I know how to do the problem in terms of d and h, but the d/l and h/l terms are throwing me off

2. Sep 27, 2011

### Ignea_unda

Welcome to PF, Expat09.

If you look at all the rest of the terms, all of them are dimensionless. By this I mean, they have no units.

$\theta$ is in radians, which are dimensionless
$\alpha$ and $\beta$ are just constants to scale h and l.

Therefore, to make h and d dimensionless, the author chose a common length, l, to make it so there are no units for d/l and h/l.

Does this help at all?