A spring of unstretched length $l$ has a mass $m$ with one end fixed to a rigid support .Assuming spring to be made of a uniform wire, the kinetic energy possessed by it if its free end is pulled with uniform velocity $v$ is
$\frac {1}{2}\,mv^2$
$mv^2$
$\frac {1}{3}\,mv^2$
$\frac {1}{6}\,mv^2$
A body of mass $5\; kg$ is moving with a momentum of $10\; kg m / s$. A force of $0.2\; N$ acts on it in the direction of motion of the body for $10\; sec$. Find the increase in its kinetic energy.
The kinetic energy $k$ of a particle moving along a circle of radius $R$ depends on the distance covered $s$ as $k = a{s^2}$ where $a$ is a constant. The force acting on the particle is
A spring is compressed between two toy carts of masses $m_1$ and $m_2$. When the toy carts are released the spring exerts equal and opposite forces for the same time $t$ on each toy cart. If the coefficients of friction $\mu $ between the ground and the toy carts are equal, then the displacement of the toy carts are in the ratio
Two bodies of masses $m$ and $4 \,m$ are moving with equal $K.E.$ The ratio of their linear momentums is
Which of the following graphs represents the graphical relation between momentum $(p)$ and kinetic energy $(K)$ for a body in motion?