A particle moves in a circular orbit under the action of a central attractive force inversely proportional to the distance ‘r’. The speed of the particle is 

(1) Proportional to r²

(2) Independent of r

(3) Proportional to r

(4) Proportional to 1/r

Two masses M and m are attached to a vertical axis by weightless threads of combined length l. They are set in rotational motion in a horizontal plane about this axis with constant angular velocity ω. If the tensions in the threads are the same during motion, the distance 'x' of M from the axis is- 

(1) $\frac{Ml}{M+m}$

(2) $\frac{ml}{M+m}$

(3) $\frac{M+m}{M}l$

(4) $\frac{M+m}{m}l$

A 500 kg car takes a round turn of radius 50 m with a velocity of 36 km/hr. The centripetal force is 

(1) 250 N

(2) 750 N

(3) 1000 N

(4) 1200 N

A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved 

(1) 14 m/s

(2) 3 m/s

(3) 3.92 m/s

(4) 5 m/s

A body of mass 5 kg is moving in a circle of radius 1m with an angular velocity of 2 radian/sec. The centripetal force is 

(1) 10 N

(2) 20 N

(3) 30 N

(4) 40 N

A stone of mass of 16 kg is attached to a string 144 m long and is whirled in a horizontal circle. The maximum tension the string can withstand is 16 Newton. The maximum velocity of revolution that can be given to the stone without breaking it will be-

(1) 20 ms^–1

(2) 16 ms^–1

(3) 14 ms^–1

(4) 12 ms^–1

Find the maximum velocity for skidding for a car moved on a circular track of radius 100 m. The coefficient of friction between the road and tyre is 0.2 

(1) 0.14 m/s

(2) 140 m/s

(3) 1.4 km/s

(4) 14 m/s

A ball of mass 0.1 Kg is whirled in a horizontal circle of radius 1 m by means of a string at an initial speed of 10 rpm. Keeping the radius constant, the tension in the string is reduced to one quarter of its initial value. The new speed is:

A cyclist riding the bicycle at a speed of $14\sqrt{3}$ms^–1 takes a turn around a circular road of radius $20\sqrt{3}$m without skidding. Given g = 9.8 ms^–2, what is his inclination to the vertical?

(1) 30^o

(2) 90^o

(3) 45^o

(4) 60^o

A point mass m is suspended from a light thread of length l, fixed at O, and is whirled in a horizontal circle at a constant speed as shown. From your point of view, stationary with respect to the mass, the forces on the mass are:

1.		2.
3.		4.