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

A block of mass 10 kg is moving in x-direction with a constant speed of 10 m/sec. It is subjected to a retarding force F = 0.1 x joule/metre during its travel from x = 20 metre to x = 30 metre. Its final kinetic energy will be

A
475 joule
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
450 joule
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
275 joule
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
250 joule
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 475 joule
We know that,
Change in kinetic energy = work done on the object by force
Here, work done Fdx=30200.1xdx
=0.1[x22]3020=0.12[302202]
=0.05[900400]=0.05×500=25 joule
Now, initial kinetic energy
=12×10×100=500 joule
Final kinetic energy = 500 -25 = 475 joule
[Direction of force is opposite to direction of motion]

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
The Work Done as a Dot-Product
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon