wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A disc of mass 100 g is kept floating horizontally in the air by firing bullets each of mass 5 g with the same velocity at the same rate of 10 bullets per second. The bullets rebound at the same speed in opposite direction. Then, the velocity of each bullet at the time of impact is: (Take g=10 m/s2)

A
1000 m/s
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
100 m/s
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
50 m/s
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
10 m/s
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D 10 m/s
Mass of the disc md=100 g=0.1 kg
Mass of the bullet mb=5g=0.005 kg

Let the speed of each bullet be v. The bullets rebound at the same speed in the opposite direction.
Hence change in speed of each bullet =v(v)=2v
Change in momentum of bullets per sec = Force applied on the disc
i.e n×mb×2v=md×g
10×0.005×2×v=0.1×10
v=12×0.005×10=10 m/s

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Summary and Misconceptions
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon