posted by GRISSELL .
At he lowest point in its swing, a 2.5 kilogram pendulum bob has 40 joules of kinetic energy. How high will it swing when it reaches the highest point in its swing?
40/2.5 x 9.8 = 1.63 joules
conservation of mech energy...
look at two spots, when the bob is at the lowest, and the highest...
KE (lowest) + KE (highest) = U (lowest ) + U (highest)
40J + 0J = 0J + mgh
40J = 2.5kg(9.81m/s^2)(height)
height = 1.6309m