In a tug-of-war contest,two men pull on a horizontal rope from opposite sides. The winner will be the man who

Two situations are shown in figures $(a)$ and $(b)$. In each case,$m_1 = 3 \ kg$ and $m_2 = 4 \ kg$. If $a_1$ and $a_2$ are the respective accelerations of the blocks in these situations,then the values of $a_1$ and $a_2$ are respectively [ $g = 10 \ ms^{-2}$ ]

$A$ constant force $F$ is applied in the horizontal direction as shown. If the contact force between $M$ and $m$ is $N$ and the contact force between $m$ and $M'$ is $N'$,then:

Can the work done by a frictional force be positive or negative?

Which of the following is not a method of reducing friction?

Consider the diagram shown below in which two masses of $m$ and $2m$ are placed on a fixed triangular wedge. The coefficient of friction between block $A$ (mass $m$) and the wedge is $\mu_A = 2/3$,while that for block $B$ (mass $2m$) and the wedge is $\mu_B = 1/3$. Find the acceleration of the system.