Question

An object of mass 1kg falls from a height of 20m and bounces back to a height of 5m. What is the change in momentum of the ball in kgm/s

Answer 1

for downward motion ;
u=0 m/s
a=10 m/s²
s=20 m
using v²- u²=2as
v= 20m/s
for upward motion;
v=0 m/s
a=10 m/s²
s=5 m using v² – u²=2as
u= -10 m/s
I=mv – mu
I=20+10=30 kg m/s