$F_{\text {net }}=m a=F \cos \theta-m g-\mu F \sin \theta$ $\int_{0}^{0} \mathrm{mdv}=\int_{0}^{\mathrm{t}_{0}}(\mathrm{F} \cos \theta-\mathrm{mg}-

$\frac{{mg \times \pi }}{{2\left( {1 - \mu } \right)}}$

$F_{\text {net }}=m a=F \cos \theta-m g-\mu F \sin \theta$ $\int_{0}^{0} \mathrm{mdv}=\int_{0}^{\mathrm{t}_{0}}(\mathrm{F} \cos \theta-\mathrm{mg}-\mu \mathrm{F} \sin \theta) \mathrm{dt}$ $\frac{\pi}{2}=\theta_{0} \times t_{0} \& \theta=\theta_{0} \times t$ $\Rightarrow F=\frac{m g \times \pi}{2(1-\mu)}$

English

4-2.FrictionDifficult

A block of mass $m$ (initially at rest) is sliding up (in vertical direction) against a rough vertical wall with the help of a force $F$ whose magnitude is constant but direction is changing. $\theta = {\theta _0}t$ where $t$ is time in sec. At $t$ = $0$ , the force is in vertical upward direction and then as time passes its direction is getting along normal, i.e., $\theta = \frac{\pi }{2}$ .The value of $F$ so that the block comes to rest when $\theta = \frac{\pi }{2}$ , is

A
$\frac{{mg \times \pi }}{{2{\theta _o}}}$
B
$\frac{{mg \times \pi }}{{2\left( {1 - \mu } \right){\theta _o}}}$
C
$\frac{{mg \times \pi }}{{\left( {1 - \mu } \right)}}$
D
$\frac{{mg \times \pi }}{{2\left( {1 - \mu } \right)}}$

Std 11
Physics

A block of mass $2 kg$ slides down an incline plane of inclination $30^o$. The coefficient of friction between block and plane is $0.5$. The contact force between block and plank is :

Medium

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A horizontal force of $10 \,N$ is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is $0.2$. the weight of the block is ........ $N$

Easy

[AIEEE 2003]

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......... $m/s^2$ is magnitude of acceleration of a block moving with speed $10\,m/s$ on a rough surface if coefficient of friction is $0.2$.

Easy

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A pen of mass $m$ is lying on a piece of paper of mass $M$ placed on a rough table. If the coefficients of friction between the pen and paper and the paper and the table are $\mu_1$ and $\mu_2$, respectively. Then, the minimum horizontal force with which the paper has to be pulled for the pen to start slipping is given by

Advanced

[KVPY 2010]

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If the normal force is doubled, the coefficient of friction is

Easy

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Similar Questions

A block of mass $2 kg$ slides down an incline plane of inclination $30^o$. The coefficient of friction between block and plane is $0.5$. The contact force between block and plank is :

A horizontal force of $10 \,N$ is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is $0.2$. the weight of the block is ........ $N$

......... $m/s^2$ is magnitude of acceleration of a block moving with speed $10\,m/s$ on a rough surface if coefficient of friction is $0.2$.

If the normal force is doubled, the coefficient of friction is