CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Q4:

4. An open lift is moving upward with constant velocity 10 ms. A ball is thrown upward with velocity 20 m/s relative to the ground. Find after what time the ball hits the lift again.
(A) 2 s (B) 3 s (C) 4 s (D) 5 s

Open in App
Solution

Dear student,

The initial speed of the ball, ub=20 m/sAs the ball is moving upward and the acceleration due to gravity is acting downward, sAcceleration of the ball, ab=-10 m/s2Let in time t, the ball meets the lift.The distance travelled by the ball in time t,s=ubt+12abt2s=20t-5t2 ...(1)The speed of the lift, ul=10 m/sAcceleration of the lift, al=0m/sThe distance travelled by the ls=ult+12alt2s=10t ...(2)Subtracting equation (1) from equation (2), we get0=-10t+5t25t(t-2)=0Therefore, t=2 sRegards

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Acceleration Due to Gravity
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon