A ball of mass m travelling at a speed v hits a rod of the same mass m and length L as shown in the figure below. After the collision , the ball sticks to the rod.Find the speed of the ball after collision.
A
4v5
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
3v5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2v5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
v5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is A4v5 Conserving the momentum we get, mv=m(vcm+ωL2)+mvcm 2v=4vcm+ωL _____(i)
Conserving the angular momentum we get, mvL2=m(vcm+ωL2)+ml2ω12
⇒3v=3vcm+2ωl ______(ii)
Solving (i) and (ii) vcm=v5
and ω=6v5l
Speed of the ball wrt the ground v′=vcm+ωl2 v′=4v5