A ball with a mass of #50 g# is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of #16 (kg)/s^2# and was compressed by #2/5 m# when the ball was released. How high will the ball go?

Acoording to energy conservation, # "gain in potential energy of the ball"="loss of energy stored in the compressed spring"#
thus, #frac{1}2 xx k xx(x)^2= mxxgxxh#
or,#h=frac{16xx4}25# {on simplification} #h# comes out to be 2.56 metres