Laws of Motion ...

The one which does not represent a force in any context is:

If a body of mass $$5\ g$$ initially at rest is acted upon by a force of $$50$$ dynes for $$3\ s$$. Then the impulse will be

A motor car is travelling at speed of $$30m/s$$ on a circular road of radius $$500m$$. If the speed of the car is increasing at the rate of $$2.0m/{ s }^{ 2 }$$, then the total acceleration will be

A block of mass $$M$$ at the end of the string is whirled round a vertical circle of radius $$R$$. The critical speed of the block at the top of the swing is

A railway carriage has its centre of gravity at a height of $$ 1 m $$ above the rails , which are $$ 1.5 m $$ apart.The maximum safe speed at which it could travel round an unbanked curve of radius $$ 100 m $$ is 

A particle tied to a string describes a vertical circular motion of radius r continually. If it has a velocity $$\sqrt{3gr}$$ at the highest point, then the ratio of the respective tensions in the string holding it at the highest and lowest points is

A batsman deflects a ball by an angle of $$45^o$$ without changing its initial speed which is equal to $$54$$km/hr. Mass of the ball is $$0.15$$kg. What is the impulse imparted to the ball?

A pendulum string of length $$l$$ is moved upto a horizontal position and released as shown in figure. If the mass of pendulum is $$m$$, then what is the minimum strength of the string that can withstand the tension as the pendulum passes through the position of equilibrium? 
(neglect mass of the string and air resistance)

Two blocks of masses $${m}_{1}$$ and $${m}_{2}$$ are connected by spring constant $$K$$. Initially the spring is at its natural length. The coefficient of friction between the bars and the surface is $$\mu$$. What minimum constant force has to be applied in the horizontal direction on the block of mass $${m}_{1}$$, in order to shift the other block?

Two people push a car for 3 sec, with a combined net force of 200 N.The impulse provided to the car............