What mass of water must fall 12m in order to lose 10,800J of gravitational potential energy ?
Potential energy = (mass) x (gravity) x (height)
10,800J = (mass) x (9.8 m/s²) x (12m)
Mass = (10,800J) / (9.8 m/s² x 12m)
Mass = (10,800 / 9.8 x 12) (Joule-sec²/m²)
(Units: Joule-sec²/m² = N-m-sec²/m² = (kg-m/s²)-m-sec²/m² = kg )
Mass = 91.8 kg
