Question

PE=30J, m=?, g=10m/s2, h=10m

Answer 1

Based on the given, this is probably a gravitational potential energy problem (PEgrav). The formula for PEgrav is:

PEgrav = mgh

Where:
m = mass (kg)
g = acceleration due to gravity
h = height (m)

With this formula you can derive the formula for your unknown, which is mass. First put in what you know and then solve for what you do not know.

$PEgrav=mgh$
$30J=m(10)(10[tex] \frac{30}{100} =m$)[/tex]

Do operations that you can with what is given first.

$30J=m(100m)$

Transpose the 100 to the other side of the equation. Do not forget that when you transpose, you do the opposite operation.

$\frac{30}{100} =m$

m = 0.30kg