Question

A ball of mass 0.1 kg is thrown vertically upwards with an initial velocity of 80 m/s . Calculate the potential energy (i) half way up (ii) at its maximum height. What's it's kinetic energy as it leaves the ground?

Answer 1

Let's calculate the maximum height

H=v^2/2g=320mH=v

2

/2g=320m

PE=mgh=0.1*10*320=320 J

at halfway up PE will be half of max = 320/2=160 J

KE will be equal to PEmax=320 J