CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
0
You visited us 0 times! Enjoying our articles? Unlock Full Access!
Question

A ball of mass 50 g is dropped from a height of 20 m.A boy on the ground hits the ball vertically upwards with a bat with an average force of 200 N, so that it attains a vertical height of 45 m. The time for which the ball remains in contact with the bat is [Take g= 10 m/s2]

A
1/20th of a second
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
1/40th of a second
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
1/80th of a second
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
1/120th of a second
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 1/80th of a second
Velocityoftheballjustbeforehittingthebat=V1V12=02+2gs=2×10×20=400V1=20m/s,V1isdownwardsheightattainedbytheballafterbeinghit:45mThespeedjustafterbeinghitbythebat=V20=V222gsV22=2×10×45=900V2=30m/sec(upwards)Changeinvelocity=V2V1=30(20)=50m/sChangeinmomentum=mV2mV1=mΔV=501000×50=2.5kgm/sforce=ΔpΔt=200NΔt=2.5200=180sec
Hence,
option (C) is correct answer.

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
F=ma
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon