Question

What is the maximum Truck Bed Height you can successfully load a 5 W piano on by 2 friends?

Answer 1

Assume the two friends can perform a certain amount of work, call it $E$. Then the height is defined by

$$h=\frac{E}{W},$$

where $W$ - weight. So, if the piano weigh 5 times more, the height is

$$h_1=\frac{E}{5W}=\frac h5.$$

The maximum Truck Bed Height is 5 times lower.