Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  • A block of mass m = 8 Kg welded with a light string of stiffness k = 400 M/m is in equilibrium on an inclined plane with the angle of inclination <img alt="\theta = 30 \degree" src="/latex-ima

A block of mass m = 8 Kg welded with a light string of stiffness k = 400 M/m is in equilibrium on an inclined plane with the angle of inclination \theta = 30 \degree. If a variable external force is applied slowly till spring comes to its relaxed position, find work done by spring force (g =10 m/s) 

Option: 1

1 J 


Option: 2

2 J 


Option: 3

4 J 


Option: 4

6 J 


Answers (1)

best_answer

Work done by restoring force -

W= -\frac{1}{2}\: kx^{2}

- wherein

Restoring force f=-kx (spring force)

Initially, block is at equilibrium 

 k x_i = mg \sin \theta

x_i =\frac{ mg \sin \theta }{k}

When the block is pulled up by an external force to bring the spring to a relaxed length x_f = 0

 W_{sp} = - \frac{1}{2} [ x _{f}^{2}- x_{i}^{2}] = - \frac{k}{2} [ 0 - \left ( \frac{mg \sin \theta }{k} \right )^2 ]

W_{sp} = \frac{1}{2} \frac{ \left ( mg \sin \theta\right )^2 }{k} = \frac{1}{2} \times \frac{(8 \times 10 \times \frac{1}{2})^2}{400} = 2   

= 2J

Posted by

Ritika Kankaria

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

Centre forms committee to tackle coaching dependency, dummy schools, examine JEE, NEET pressure
anam-khan

BSc Nursing NEET cut-offs for AIQ seats, central universities; counselling process, fee details
anam-khan

NEET cut-off trends for MBBS in Tamil Nadu government, private medical colleges; counselling underway

Latest Question