A coin is dropped in a lift. It takes time $t_1$ to reach the floor when lift is stationary. It takes time $t_2$ when lift is moving up with constant acceleration, then
$t_1 = t_2$
$t_1 > t_2$
$t_2 < t_1$
$t_1 > t_2$
A man of mass $m_1$ is standing on a platform of mass $m_2$ kept on a smooth horizontal surface. If the man starts moving on the platform with a velocity $v$ relative to the platform, then recoil velocity of platform is
A weight can be hung in any of the following four ways by string of same type. In which case is the string most likely to break?
A child is standing at one end of a long trolley moving with a speed $v$ on a smooth horizontal floor. If the child starts running towards the other end of the trolley with a speed $u$ , the centre of mass of the system (trolley + child) will move with a speed
A truck starting from rest moves with an acceleration of $5\,m / s ^2$ for $1 sec$ and then moves with constant velocity. The velocity w.r.t. ground v/s time graph for block in truck is (Assume that block does not fall off the truck)
A block of mass $m$ lying on a rough horizontal plane is acted upon by a horizontal force $P$ and another force $Q$ inclined an at an angle $\theta$ to the vertical. The minimum value of coefficient of friction between the block and the surface for which the block will remain in equilibrium is :