A body of constant mass $m=1 \mathrm{kg}$ moves under variable force $F$ as shown. If at $t=0, S=0$ and velocity of the body is $\sqrt{20} \mathrm{m} {\mathrm{s}}^{-1}$ and the force is always along direction of velocity, then choose the incorrect options 

 

A block of mass $m$ is attached to one end of a massless spring of spring constant $k$. The other end of the spring is fixed to a wall. The block can move on a horizontal rough surface. The coefficient of friction between the block and the surface is $\mu$. The block is released when the spring has a compression $\frac{2\mu mg}{k}$of then choose the incorrect option(s): 

A man applying a force $F$ upon a stretched spring is stationary in a compartment moving with constant speed $v$. The compartment covers a distance $L$ in some time $t$.

A block of mass $2 \mathrm{kg}$ is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force $F=40 \mathrm{N}$. At $t=0$ the system is at rest as shown. Then in the time interval $t=0$ to $t=\frac{2}{\sqrt{10}} \mathrm{s}$, pick the correct statement(s). (Take, $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)

A force $F$ (power of $F$ is $p=$ constant) is applied on block $A$ of mass $m$ as shown in the figure, $F$ is parallel to the inclined plane. Then:

Two bodies of mass $m_1$ and $m_2 (m_2>m_1)$ are connected by a light inextensible string which passes through a smooth fixed pulley as shown. Then choose the correct option(s) 

The given plot shows the variation of $U$, the potential energy of interaction between two particles with the distance separating them is $r$. Then which of the following statements is/are correct: