# How much work would it take to push a  4 kg  weight up a  5 m  plane that is at an incline of  pi / 4 ?

It takes $138.7 J$
First of all we have to find the value of $h$, the variation in altitude.
We use trigonometry: h=5m*sin45°=3.5m
To find work we use the equation $W = m g h = 4 k g \cdot 9.81 \frac{m}{s} ^ 2 \cdot 3.5 m = 138.7 J$