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

The bob of a pendulum is released from a horizontal position A as shown in the figure. The length of the pendulum is 2 m. If 10% of the initial energy of the bob is dissipated as heat due to the friction of air, what would be the speed of the bob when it reaches the lowermost point B? Take g=10 ms2.


A

3 ms1

No worries! We‘ve got your back. Try BYJU‘S free classes today!
B

4 ms1

No worries! We‘ve got your back. Try BYJU‘S free classes today!
C

5 ms1

No worries! We‘ve got your back. Try BYJU‘S free classes today!
D

6 ms1

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D

6 ms1


PE at A = mgh. Since 10% of this energy is lost, KE at point B =mgh×90100=0.9 mgh.
Now, 12mv2=0.9 mgh
v2=1.8 gh=1.8×10×2=36
v=6 ms1
Hence, the correct choice is (d).


flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Conservative Forces and Potential Energy
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon