Exercise (Conceptual Questions)

A particle is in a straight line motion with uniform velocity. A force is not required:-

A body of mass $2 \mathrm{kg}$ moving on horizontal surface with an initial velocity of $4 \mathrm{m}/\mathrm{s}$ comes to rest after $2 \mathrm{s}$. If one wants to keep this, body moving on the same surface with a velocity $4 \mathrm{m}/\mathrm{s}$, the force required is

The ratio of gravitational mass to inertial mass is equal to : 
 

A block of metal weighing $2 \mathrm{kg}$ is resting on a frictionless plane. It is struck by a jet releasing water at the rate of $1 \mathrm{kg} {\mathrm{s}}^{-1}$ and at a speed of $5 {\mathrm{ms}}^{-1}$. The initial acceleration of the block is

A monkey of mass $20\mathrm{kg}$ is holding a vertical rope. The rope will not break when a mass of $25\mathrm{kg}$ is suspended from it but will break if the mass exceeds $25\mathrm{kg}$. What is the maximum acceleration with which the monkey can climb up along the rope ? $\left(g=10\mathrm{m}/{\mathrm{s}}^2\right)$

A block of mass $m$ is placed on a smooth wedge of inclination $\text{θ}$.The whole system is accelerated horizontally so that block does not slip on the wedge. The force exerted by the wedge on the block($g$ is acceleration due to gravity) will be

Two blocks of masses $2 \mathrm{kg}$ and $1 \mathrm{kg}$ are in contact with each other on a frictionless table. When a horizontal force of $3.0 \mathrm{N}$ is applied to the block of mass $2 \mathrm{kg}$ the value of the force of contact between the two blocks is- 

One end of a uniform wire of length $L$ and weight $w$ is attached rigidly to a point in the roof and weight $w_1$ is suspended from its lower end. If $S$ is the area of cross-section of the wire, the stress in the wire at a height of $\frac{3L}{4}$ from its lower end is