A body of mass m is moving in a circle of radius r with a constant speed v . force on body is frac{m

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5.Work, Energy, Power and Collision

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A body of mass $m$ is moving in a circle of radius $r$ with a constant speed $v$. The force on the body is $\frac{mv^2}{r}$ and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle

A

$\frac{{m{v^2}}}{r} \times \pi r$

B

Zero

C

$\frac{{m{v^2}}}{{{r^2}}}$

D

$\frac{{\pi {r^2}}}{{m{v^2}}}$

Solution

Force always remains perpendicular to the direction of displacement. work done $W = F·d\, cos \theta $ when $\theta = 90^o$ then $W = 0$

Standard 11

Physics

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