A body moves with velocity $v = ln x\ m/s$ where $x$ is its position. The net force acting on body is zero at
$0 \,\, m$
$x = e^2 \,\,m$
$x = e \,\, m$
$x = 1\,\, m$
“Momentum and changes in momentum are not always in same direction”. Explain by suitable example.
A spherical body of mass $100 \mathrm{~g}$ is dropped from a height of $10 \mathrm{~m}$ from the ground. After hitting the ground, the body rebounds to a height of $5 \mathrm{~m}$. The impulse of force imparted by the ground to the body is given by : (given $\mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2$ )
Figures $(a), (b), (c)$ and $(d)$ show variation of force with time.
The impulse is highest in figure.
Explain -product of mass and velocity is important in producing effect of force.
A solid horizontal surface is covered with a thin layer of oil. A rectangular block of mass $m =0.4 kg$ is at rest on this surface. An impulse of $1.0 N s$ is applied to the block at time $t =0$ so that it starts moving along the $x$-axis with a velocity $v ( t )= v _0^{ e ^{-1 / \tau}}$, where $v_0$ is a constant and $\tau=4 s$. The displacement of the block, in metres, at $t=\tau$ is. . . . . . . Take $e ^{-1}=0.37$