Centripetal Acceleration

Q. The magnitude of the centripetal force acting on a body of mass mexecuting uniform motion in a circle of radius rwith speed vis

1. $\frac{v}{r^{2}m}$
2. $\frac{v}{rm}$
3. $\frac{m{v}^2}{r}$
4. $mvr$

Q. On a railway curve, the outside rail is laid higher than the inside one so that resultant force exerted on the wheels of the rail car by the tops of the rails will

1. Have a horizontal inward component
2. Be vertical
3. Equilibriate the centripetal force
4. Be decreased

Q.

A car moving on a horizontal road may be thrown out of the road in taking a turn

1. Due to lack of sufficient centripetal force

2. Due to rolling frictional force between tyre and road

3. Due to the reaction of the ground

4. By the gravitational force

Q.

A 100 kg car is moving with a maximum velocity of 9 m/s across a circular track of radius 30 m. The maximum force of friction between the road and the car is

1. 1000 N

2. 706 N

3. 200 N

4. 270 N

Q.

A stone is tied to one end of a string 50 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 10 revolutions in 20 s, what is the magnitude of acceleration of the stone

1. $493cm/s^2$

2. $720cm/s^2$

3. $720cm/s^2$

4. $990cm/s^2$

Q.

A cycle wheel of radius 0.4 m completes one revolution in one second then the acceleration of a point on the cycle wheel will be

1. $0.8m/s$

2. $0.4m/s$

3. $1.6{\pi }^{2}m/s^2$

4. $0.4{\pi }^{2}m/s^2$

Q.

Two particles of equal masses are revolving in circular paths of radii $r_{1}and{r}_2$ respectively with the same speed. The ratio of their centripetal forces is

1. $\frac{r_2}{r_1}$

2. ${\left(\frac{r_1}{r_2}\right)}^2$

3. ${\left(\frac{r_2}{r_1}\right)}^2$

4. $\sqrt{\frac{r_2}{r_1}}$

Q.

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 R.P.M. Keeping the radius constant, the tension in the string is reduced to one quarter of its initial value. The new speed is

1. 5 r.p.m.

2. 14 r.p.m.

3. 10 r.p.m.

4. 20 r.p.m.

Q.

A body is revolving with a constant speed along a circle. If its direction of motion is reversed but the speed remains the same, then which of the following statement is true

1. The centripetal force will not suffer any change in magnitude

2. The centripetal force will have its direction reversed

3. The centripetal force will not suffer any change in direction

4. The centripetal force would be doubled

Q.

A car sometimes overturns while taking a turn. When it overturns, it is

1. The inner wheel which leaves the ground first

2. The outer wheel which leaves the ground first

3. Both the wheels leave the ground simultaneously

4. Either wheel leaves the ground first