A sphere of mass m and radius r is projected in a gravity free space with speed v. If coefficient of viscosity of the medium in which it moves is `1/(6pi)` , the distance travelled by the body before it stops isA. `(mv)/(2r)`B. `(2mv)/r`C. `(mv)/r`D. `(mv)/(4r)`

A sphere of mass m and radius r is projected in a gravity free space w

1.	A sphere of mass m and radius r is projected in a gravity free space with speed v. If coefficient of viscosity of the medium in which it moves is `1/(6pi)` , the distance travelled by the body before it stops isA. `(mv)/(2r)`B. `(2mv)/r`C. `(mv)/r`D. `(mv)/(4r)`
Answer» Correct Answer - C The only force acting on the body is the viscous force Here, `.m(vdv)/(dx) =-6 pi eta r v=-rv` `rArr int_(v)^(0)mdv-int_(0)^(x)-rdx rArr x=(mv)/f`

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A sphere of mass m and radius r is projected in a gravity free space with speed v. If coefficient of viscosity of the medium in which it moves is `1/(6pi)` , the distance travelled by the body before it stops isA. `(mv)/(2r)`B. `(2mv)/r`C. `(mv)/r`D. `(mv)/(4r)`

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