wiz-icon
MyQuestionIcon
MyQuestionIcon
2
You visited us 2 times! Enjoying our articles? Unlock Full Access!
Question

Two metal balls of masses 10 kg and 20 kg, moving in opposite directions on a frictionless floor, collide elastically. If the velocities of the balls are 3 m/s and 1 m/s respectively before collision as shown in the figure, then the velocities of the balls after collision are respectively


A
53 m/s towards right, 73 m/s towards right
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
53 m/s towards left, 73 m/s towards right
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
73 m/s towards left, 53 m/s towards right
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
53 m/s towards left, 73 m/s towards left
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 73 m/s towards left, 53 m/s towards right
Given,
Mass of metal ball 1 (m1)=10 kg
Mass of metal ball 2 (m2)=20 kg
Speed of metal ball 1 before collision (u1)=3 m/s
Speed of metal ball 2 before collision (u2)=1 m/s

Let the velocities after collision be v1 and v2.
Using law of conservation of momentum (taking rightward +ve):
m1u1+m2u2=m1v1+m2v2
10(3)+20(1)=10v1+20v2
v1+2v2=1 ...(1)
For elastic collision, e=1
v2v1=u1u2
v2v1=4 ...(2)

From (1) and (2), we get
3v2=5v2=53 m/s (right)
& v1=12v2=1103=73 m/s (left)


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