# How much work would it take to push a  2 kg  weight up a  9 m  plane that is at an incline of  pi / 4 ?

Jun 3, 2017

I got $125 J$

#### Explanation:

Let us consider the diagram:

with:
$\alpha = \frac{\pi}{4}$
$d = 9 m$

and the fact that the work done will result in an increase of Potential Energy (Gravitational) $U$ so that:

$W = U = m g h$

but $h = \mathrm{ds} \in \left(\alpha\right)$
so:

$W = m g \cdot \mathrm{ds} \in \left(\alpha\right) = 2 \cdot 9.8 \cdot 9 \sin \left(\frac{\pi}{4}\right) = 124.7 \approx 125 J$