Laws of Motion ...

A hockey ball of mass 200 g travelling at $$10\ ms^{-1}$$ is struck by a hockey stick so as to return it along its original path with a velocity of $$5\ ms^{-1}$$. Calculate the change of momentum which occurred in the motion of the hockey ball by the force applied by the hockey stick:

A boy holds a pendulum in his hand while standing at the edge of a circular platform of radius $$r$$ rotating at an angular speed $$\omega$$. The pendulum will hang at an angle $$\theta$$ with the verticle such that

Figures $$I, II, III\ and\ IV$$ depicts variation of force with time. In which situation impulse will be maximum?

A particle of mass $$'m'$$ describes a circle of radius $$(r)$$. The centripetal acceleration of the particle is $$\displaystyle\frac{4}{r^2}$$. The momentum of the particle:

A mass tied to a string moves in a vertical circle with a uniform speed of $$5\;m/s$$ as shown. At the point $$P$$ the string breaks. The mass will reach a height above $$P$$ of nearly: $$(g=10\ m/s^{2})$$

In a vertical circle of radius $$(r)$$, at what point in its path a particle may have tension equal to zero:

A stone attached to one end of a string is whirled in a vertical circle. The tension in the string is maximum when

A particle is moving in a vertical circle, the tension in the string when passing through two position at angle $$30^{\circ}$$ and $$60^{\circ}$$ from vertical from lowest position are $$T_1$$ and $$T_2$$ respectively, then 

A pendulum bob has a speed $$3\;m/s$$ while passing through its lowest position, length of the pendulum is $$0.5\;m$$ then its speed when it makes an angle of $$60^{\circ}$$ with the vertical is

A rod of weight $$w$$ is supported by two parallel knife edges $$A$$ & $$B$$ and is in equilibrium in a horizontal position. The knives are at a distance $$d$$ from each other. The center of mass of the rod is at a distance $$x$$ from $$A.$$ The normal reactions at $$A$$ and $$B$$ will be