CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

Two stones are dropped down simultaneously from different heights with initial speed u1=0 and u2=30 m/s respectively. If the initial distance between them is 10 m and mass of the first stone is twice that of the second stone, find the velocity of their COM after 2 s. [Take g=10 m/s2]

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

The correct option is B 30 m/s
Given, u1=0,u2=30 m/s
Let the mass of the second stone be m. Then, mass of the first stone will be 2m.
Acceleration of COM is g m/s2
Initial velocity of COM,
ucom=m1u1+m2u2m1+m2
=2m×0+m×30m+2m=10 m/s
Velocity of COM after 2 s will be
vcom=ucom+acom×t
vcom=10+10×2=30 m/s

flag
Suggest Corrections
thumbs-up
0
BNAT
mid-banner-image