Question

A point object of mass2kg is moved from point a to b Very slowly on a curved path by applying a tangential force on curved path as shown in figures the find the work done by external forces in moving the body. Given that Us=0.3 Uk=0.1
give answer step by step
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Answer 1

Answer:

400 J

Explanation:

1) Since, Point object is moved  very slowly from A to B .

=> Kinetic energy is 0 at point A and B.

Since, A and B are at same height from ground.

Work done by Gravity = 0

$=>W_g=0$

2) Work done by friction

l= 200 m

$W_f=-\mu_kmg*l=-0.1*2*10*200=-400J$

Let the work done by tangential force be $W_T$.

3) Now, By Applying Work Energy Theorem ,

$W_g+W_f+W_T=\Delta KE\\ \\=>0-400+W_T=0-0=0\\ \\=>W_T=400 J$

Hence, Work done by tangential force is 400 J.