## College Physics (4th Edition)

The potential energy of the descending mass is converted to heat inside the water (usually use Potential energy if there is a height). h= (30)(1.25m) As it descends 30 times m= ? $\Delta$P = 1000 J g= 9.8 $m/s^{2}$ Let $\Delta$$P_{grav} = \Delta$$E_{interal energy}$ $\Delta$P=mgh Rearange the equation to make m your subject of the equation m=$\frac{\Delta U}{g.h}$ =$\frac{1000J}{(9.8 m/s^{2})(30)(1.25m))}$ =2.72kg