Two balls of masses ${m_1}$ and ${m_2}$ are separated from each other by a powder charge placed between them. The whole system is at rest on the ground. Suddenly the powder charge explodes and masses are pushed apart. The mass ${m_1}$ travels a distance ${s_1}$ and stops. If the coefficients of friction between the balls and ground are same, the mass ${m_2}$ stops after travelling the distance
${s_2} = \frac{{{m_1}}}{{{m_2}}}{s_1}$
${s_2} = \frac{{{m_2}}}{{{m_1}}}{s_1}$
${s_2} = \frac{{m_1^2}}{{m_2^2}}{s_1}$
${s_2} = \frac{{m_2^2}}{{m_1^2}}{s_1}$
The force required just to move a body up an inclined plane is double the force required just to prevent the body from sliding down. If $\mu $ is the coefficient of friction, the inclination of plane to the horizontal is
A small body slips, subject to the force of friction, from point $A$ to point $B$ along two curved surfaces of equal radius, first along route $1,$ then along route $2$. Friction does not depend on the speed and the coefficient of friction on both routes is the same. In which case will the body’s speed at $B$ be greater?
In the figure, a ladder of mass $m$ is shown leaning against a wall. It is in static equilibrium making an angle $\theta$ with the horizontal floor. The coefficient of friction between the wall and the ladder is $\mu_1$ and that between the floor and the ladder is $\mu_2$. The normal reaction of the wall on the ladder is $N_1$ and that of the floor is $N_2$. If the ladder is about to slip, then
$Image$
$(A)$ $\mu_1=0 \mu_2 \neq 0$ and $N _2 \tan \theta=\frac{ mg }{2}$
$(B)$ $\mu_1 \neq 0 \mu_2=0$ and $N_1 \tan \theta=\frac{m g}{2}$
$(C)$ $\mu_1 \neq 0 \mu_2 \neq 0$ and $N _2 \tan \theta=\frac{ mg }{1+\mu_1 \mu_2}$
$(D)$ $\mu_1=0 \mu_2 \neq 0$ and $N _1 \tan \theta=\frac{ mg }{2}$
A lift is moving downwards with an acceleration equal to acceleration due to gravity. $A$ body of mass $M$ kept on the floor of the lift is pulled horizontally. If the coefficient of friction is $\mu $, if the lift is moving upwards with a uniform velocity, then the frictional resistance offered by the body is
A uniform chain of length $L$ changes partly from a table which is kept in equilibrium by friction. The maximum length that can withstand without slipping is $l$, then coefficient of friction between the table and the chain is