The body of mass 2 kg moves down the quadrant of a circle of radius 4m the velocity on reaching the lowest point is 8m/s what is the work done against friction
Answers
Answered by
6
Given:
Mass = 2 kg
Radius = 4 m
Velocity = 8 m / s
To find:
The work done against friction.
Solution:
By work energy theorem,
Work done ( normal ) + work done ( potential energy ) + work done ( friction ) = work done ( kinetic energy )
Work done ( normal ) - 0
work done ( potential energy ) - Mass * gravity * height
work done ( kinetic energy ) - 1 / 2 * Mass * velocity^2
Substituting,
We get,
0 + 9.8 * 400 + work done ( friction ) = 1 / 2 * 2 * 8 * 8
3920 + work done ( friction ) = 64
Work done ( friction ) = 64 - 3920
As work done cannot be negative,
Work done ( friction ) = 3856 J
Answered by
1
Answer:
64J
Explanation:
m=2kg
U=0
V=8m/s
W=1/2mv’2_1/2mu’2
W=1/2*2*64=64
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