Laws of Motion ...

A body of mass $$2kg$$ is lying on a floor. The coefficient of static friction is $$0.54$$. What will be the value of frictional force if the force is $$2.8N$$ and $$g=10{ ms }^{ -2 }$$?

A balloon has $$5g$$ of air. A small hole is pierced into it. The air escapes at a uniform rate with a velocity of $$4cm/s$$. If the balloon shrinks completely in $$2.5$$ seconds, then the mean force acting on the balloon is:

A body of mass $$1\ kg$$ is rotating in a vertical circle of radius $$1\ m$$. What will be the difference in its kinetic energy at the top and bottom of the circle? 

Let $$\theta$$ denote the angular displacement of a simple pendulum oscillating in a vertical plane. If the mass of the bob is m, then tension in the string is mg $$\cos\theta$$

The velocity of a particle at highest point of the vertical circle is $$\sqrt{3rg}$$. The tension at the lowest point, if mass of the particle is $$m$$, is

A stone of mass $$1\ kg$$ is tied of the end of a string $$1\ m$$ long. It is whirled in a vertical circle. If the velocity of stone at the top is $$4\ m/s$$. What is the tension in the string at the lowest point? 

For traffic moving at $$60 km/hr$$ along a smooth circular track of radius $$0.1 km$$, the correct angle of banking should be:

If a particle of mass m moving with velocity $$v_1$$ is subject to an impulse $$I$$ which produces a final velocity $$v_2$$, then $$I$$ is given by :

A rocket is moving at a constant speed in space by burning its fuel and ejecting out the burnt gases through a nozzle. 

A cricket ball of mass 500 gm strikes a bat normally with a velocity 30 m/s and rebounds with a velocity 20 m/s in the opposite direction. The impulse of the force exerted by the ball on the bat is: