Work Energy and...

A force of $$16N$$ is distributed uniformly on one surface of a cube of edge $$8cm$$. The pressure on this surface is 

In the phenomenon of work done by variable forces, the forces:

A brick of mass $$m$$ , tied to a rope , is being whirled in a vertical circle, with a uniform speed. The tension in the rope is:

A $$\vec{F}=(5\hat{i}+3\hat{j}+2\hat{k})\ N$$ is applied over a particle with displaces it from its origin to the point $$\vec{r}=(2\hat{i}-\hat{j})m$$. The work done on the particle is joule is

A particle moves from $$X = 0\ $$ to $$X = 2\ m$$ on X-axis under the effect of $$ { F } (x) = ({ 4x }^{ 3 } - { 3x }^{ 2 } + 2x + 5)\widehat { i } $$ Newton. The work done on the particle is 

A force F = $$-\frac{K}{X^2} (X \neq 0)$$ acts on a particle in x-direction. The work done by this force in displacing the particle from x = +a to x = +2a is. (Where k is a positive constant)

Given $$k_1 = 1500 \ N/m,$$ $$k_2 =500 \ N/m,$$ $$m_1 = 2 \ kg$$ and $$m_2 = 1  \ kg$$. Find potential energy stored in equilibrium: (Take $$g = 10 \ m/s^2$$)

A ball of mass $$'m'$$ moves towards a wall with a velocity $$'u'$$, the direction of motion making an angle $$\theta$$ with the surface of the wall and rebounds with the same period. The change in momentum of the ball during the collision is:

 A car of mass 400 kg travelling at 72 kmph crashes a truck of mass 4000 kg and travelling at 9 kmph in the same direction. The car bounces back with a speed of 18 kmph. The speed of the truck after the impact is

 A perfectly elastic ball $$p_{1}$$of mass 'm' moving with velocity v collides elastically with three exactly similar balls $$p_{2}$$ , $$p_{3}$$ , $$p_{4}$$  lying on a smooth table. Velocities of the four balls after collision are