Question 1 :
A stationary cannon fires a cannonball. Which of the following is NOT true immediately after the cannonball is fired?

Question 2 :
A machine has an efficiency of $25$%. Energy is fed into the machine at the rate of $1 kw$. The output power of machine is:-

Question 3 :
Calculate the work done in lifting &#160;water of 200 kg through a vertical distance of 6 m. $\left ( g=10&#160; m&#160; s^{-2} \right )$<br/>

Question 4 :
A man of mass $50kg$ climbs up a ladder of height $10m$. Calculate the increase in his potential energy. $(g=9.8ms^{-2})$

Question 5 :
&#160;The mass of a loaded truck $10$ tonnes is going at a speed of $20 \ kmph$. A box of mass $2$ tonnes slips from it and falls on the road. Find the final velocity of truck (assume that the power of the engine is constant) ?<br/>

Question 6 :
The gravitational potential energy of a body is ________ to its height&#160;above the surface of the Earth.

Question 7 :
&#160;A bullet of mass 20 gm is fired from a rifle of mass 20 kg with a muzzle velocity of $200\ ms^{-1}$. Find the velocity of recoil of the rifle.<br/>

Question 8 :
Work done by centripetal force on a body in $U.C.M.$ is

Question 9 :
Find the vertical height through which a body of mass $0.5kg$ is lifted if the energy spent in doing so is $1.0J$. Consider $g=10ms^{-2}$.

Question 10 :
A body of weight 1 newton has a potential energy of 1 joule relative to the ground when it is at a height of:

Question 11 :
A mass of $0.5\:kg$ moving with a speed of $1.5\ {m}/{s}$ on a horizontal smooth surface, collides with a nearly weightless spring of force constant $k=50 \ {N}/{m}$. The maximum compression of the spring would be&#160;

Question 12 :
Two springs have their force constants $K_{1}$ and $K_{2}$. Both are stretched till their elastic energies are equal. If the stretching forces are $F_{1}$ and $F_{2}$ then $F_{1}:F_{2}$ is equal to

Question 13 :
A bullet of mass 2.5 g moving with a velocity of $500ms^{-1}$, enters a wooden block and comes out of it with a velocity of $100ms^{-1}$. Find the work done by the bullet while passing through the wooden block.

Question 14 :
From a rifle of mass $40\ kg$, a bullet of mass $50\ g$ is fired with an initial velocity of $35\ m/s$. Calculate the initial recoil velocity of the rifle:

Question 15 :
A chain is held on a friction-less table with one third of its length hanging over the edge. The total length of the chain is $1$ and its mass is $m$. Find the work required to pull the hanging part back to the table.

Question 16 :
A bod of mass 3 kg is under a force, which causes a dip, in it is given by $ S= 1 / 3 t^2 $ ( in m) find the work done by the force in first 2 second&#160;

Question 17 :
A force $F = - K (y \widehat i + x \widehat j)$, (where $K$ is a +ve constant) acts on a particle moving in xy plane starting from origin, the particle is taken along the positive x-axis to the point ($a, 0$) and then parallel to y axis to the point ($a, a$). The total work done by force $F$ on the particle is

Question 18 :
The set of values of x for which the angle between the vectors&#160;$\displaystyle \vec{a}=x\hat{i}-3\hat{j}-\hat{k}$ and $\displaystyle \vec{b}=2x\hat{i}+x\hat{j}-\hat{k}$ is&#160;acute and the angle between the vector $\displaystyle \vec{b}$ and the axis of ordinates is obtuse, is:

Question 19 :
A ladder $'AB'$ of weight $300N$ and length $5m$ is lying on a horizontal surface. Its centre of gravity is at a distance of $2m$ from end $A$. A weight of $80N$ is attached at end $B$. The work done in raising the ladder to the vertical position with end $'A'$ in contact with the ground is.

Question 20 :
A ball which is at rest is dropped from height $h$ metre. As it bounces off the floor, its speed is $80$% of what it was just before touching the ground. The ball will then rise to nearly a height.<br/>