Question

A force of 300 N acts on a 2.5 m long and 10 kg rod initially at rest. what is the final angular momentum of the rod if the force acts on it for 8 seconds?

Answer 1

$solution$

$if F=300N$

$r=2.5m$

$m=10kg$

$u=0m/s$

$t=8s$

$from F=ma$

$300=10*a$

$a=300/10$

$a=30m/s^2$

$from v=u+at$

$v=0+30*8$

$v=240m/s$

$linear momentum$ $p = m*v.$

$=10*240$

$=2400kgm/s$

the final angular momentum $L$ $=$ distance of the object from a rotation axis$(r)$ $*$ the linear momentum$(p)$

$L=r*p$

$=2.5m*2400kgm^2/s$

$=6000kgm^2/s$