Circular Motion

Q.

The angular velocity of the second's hand of a watch is

1. rad/sec
2. rad/sec
3. rad/sec
4. rad/sec

Q.

1 astronomical unit is equal to:

1. $2.475\times {10}^{14}m$
2. $1.496\times {10}^{14}m$
3. $2.475\times {10}^{11}m$
4. $1.496\times {10}^{11}m$

Q.

What happens to the centripetal acceleration of a revolving body if you double the orbital speed v and half angular velocity ω

1. It remains unchanged

2. Is is halved

3. It is doubled

4. It is quadrupled

Q.

A scooterist is racing at a speed of 72 km/h. If the radius of the wheel is 20 cm, find the angular speed of the wheels.

Q.

Two particles of masses $m$ and $\frac{m}{2}$ are moving along the circular paths of radii $r$and $3r,$ respectively, with equal speed. What is the ratio of their accelerations?

1. $1:1$

2. $1:3$

3. $3:1$

4. $2:1$

Q.

Calculate the value of centripetal acceleration for a mass of $10kg$ performing a circular motion with $4m/s$ with the radius $0.5m$.

1. $2m/s^2$

2. $22m/s^2$

3. $32m/s$

4. $32m/s^2$

Q.

In a circular motion of a stone tied to a string, ___

1. only tangential acceleration is present

2. centripetal and tangential acceleration both are present

3. only centripetal acceleration is present

4. only centripetal force

Q.

Name the force required for uniform circular motion and state it's direction

Q. is the speed of revolution of Titan (Saturn's moon), when orbital distance is 1.22×109m and time of revolution is 16 days.

1. $7,091m{s}^{-1}$
2. $5,542m{s}^{-1}$
3. $28,366m{s}^{-1}$
4. $14,183m{s}^{-1}$

Q.

Define centripetal acceleration?

Q. It takes 10 min to cover a round of a circular rope at speed 10cm/s. If the rope is kept as a straight line, the constant acceleration needed to complete the path in 5 min is.

1. $\frac{1}{1500}$ $m{s}^{-2}$
2. $\frac{1}{1000}$ $m{s}^{-2}$
3. $\frac{1}{500}$ $m{s}^{-2}$
4. $\frac{1}{750}$ $m{s}^{-2}$

Q.

To keep an object in a fixed circular orbit, which of the following plays an important role?

1. Changing tangential velocity.

2. Linear momentum of the object

3. Centripetal acceleration

4. Mass of the object

Q.

An object travels around a circle of radius 6 m with speed 3$\pi$ m/s. Find the distance and displacement after 3 s.

1. 9π m, 0 m

2. 9π m, 6√2 m

3. 12π m, 6√2 m

4. 12π m, 0 m

Q. A body of mass, $m$, is moving in a circle of radius, $r$, with a constant speed, $v$. The work done by the centripetal force in moving the body over half the circumference of a circle is

1. $m{v}^{2}r$
2. $zero$
3. $m{v}^2/r$
4. $r^2/m{v}^2$

Q.

A particle performing a circular motion experiences___.

1. centripetal acceleration

2. angular acceleration

3. both centripetal as well as angular acceleration

4. centripetal velocity

Q.

The angular speed (w), the radius (r), and the linear speed (v) is related as

1. v=rw

2. v=r/w

3. v=w/r

4. v=2rw

Q.

The angular distance (θ), the radius (r), and the linear distance (d) is related as

1. d=r/θ

2. d=rθ

3. d=1/(2rθ)

4. d=2rθ

Q. One of saturn's moon is named as Mimas. The orbital radius of Mimas is $1.87\times$ ${10}^{8}m$ from saturn. The mean orbital period of Mimas is approximately 23 hours. Calculate the speed of Mimas with which it revolves around saturn. Assume that the path taken is circular.

1. $21,274m{s}^{-1}$
2. $7,091m{s}^{-1}$
3. $28,366m{s}^{-1}$
4. $14,183m{s}^{-1}$

Q. If KE of the particle of mass, $m$, performing Uniform Circular Motion in a circle of radius, $r$, is $E$. Find the acceleration of the particle

1. $\frac{2E}{mr}$
2. ${\left(\frac{2E}{mr}\right)}^2$
3. $2Emr$
4. $\frac{4E}{mr}$

Q.

The force which is compulsory to sustain uniform circular motion is

1. Centripetal Force which acts along the tangent

2. Centripetal Force which acts along the radius inwards

3. Centrifugal Force which acts along the radius inwards

4. Centrifugal Force which acts along the radius outwards

Q.

The direction of centripetal force will be:

1. towards the centre

2. same as the direction of tangential speed

3. same as the direction of angular speed

4. away from the centre

Q. An aeroplane flying at constant speed $105m/s$ towards East, makes a gradual turn following a circular path to fly South. The turn takes $15$ seconds to complete. The magnitude of the centripetal acceleration during the turn is

1. $\frac{7\pi }{2}m/s^2$
2. $\frac{46\pi }{3}m/s^2$
3. $14\pi m/s^2$
4. $\frac{23\pi }{6}m/s^2$

Q.

is centripetal force acting on a body performing a uniform circular motion always a constant

Q. A person travels $100\text{km}$ in the North direction and then turns right and travels $100\text{km}$. The magnitude of displacement is

1. $200\text{km}$
2. $100\sqrt{3}\text{km}$
3. None of these
4. $100\sqrt{2}\text{km}$