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

A person of mass M is sitting on a swing of length L and swinging with an angular amplitude θ0. If the person stands up when the swing passes through its lowest point, the work done by him, assuming that his centre of mass moves by a distance (<<L), is close to :

A
Mg
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
Mg(1+θ20)
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
Mg(1θ20)
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
Mg(1+θ202)
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B Mg(1+θ20)
Angular momentum conservation.
MV0L=MV1(L)
V1=V0(LL)

12MV2112MV2o=Wp+Wg

12M(V2oL2(Ll)2V2o)=WpMgl

12MV2o1(1lL)21=WpMgl

Wp=12MV2o[(1lL)21]+Mgl

=12MV2o[(1+2lL)1]+Mgl

=12MV2o2lL+Mgl

=12MV2o(gL)(2lL)+Mgl=Mgl(1+θ2o)

Put Vo in above eq. to get the final result

Vo=Aw

=θogLL

=θogL




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