If the body is moving in a circle of radius r with a constant speed v, its angular velocity is:
1. v2/r
2. vr
3. v/r
4. r/v
Two racing cars of masses \(m_1\) and \(m_2\) are moving in circles of radii \(r_1\) and \(r_2\) respectively. Their speeds are such that each makes a complete circle in the same duration of time \(t\). The ratio of the angular speed of the first to the second car is:
| 1. | \(m_1:m_2\) | 2. | \(r_1:r_2\) |
| 3. | \(1:1\) | 4. | \(m_1r_1:m_2r_2\) |
If a particle moves in a circle describing equal angles in equal times, its velocity vector:
1. remains constant.
2. changes in magnitude.
3. changes in direction.
4. changes both in magnitude and direction.
A motorcyclist going round in a circular track at a constant speed has:
1. constant linear velocity.
2. constant acceleration.
3. constant angular velocity.
4. constant force.
A particle moves with constant angular velocity in a circle. During the motion its:
| 1. | Energy is conserved |
| 2. | Momentum is conserved |
| 3. | Energy and momentum both are conserved |
| 4. | None of the above is conserved |
Two bodies of mass 10 kg and 5 kg moving in concentric orbits of radii R and r such that their periods are the same. Then the ratio between their centripetal acceleration is
1. R/r
2. r/R
3. R2/r2
4. r2/R2
A particle is moving in a horizontal circle with constant speed. It has constant:
1. Velocity
2. Acceleration
3. Kinetic energy
4. Displacement
The angular speed of a flywheel making \(120\ \text{revolutions/minute }\)is:
1. \(2 𝜋\ \text{𝑟𝑎𝑑/𝑠}\)
2. \(4 𝜋^2\ \text{𝑟𝑎𝑑/𝑠}\)
3. \(𝜋\ \text{𝑟𝑎𝑑/𝑠}\)
4. \(4 𝜋\ \text{𝑟𝑎𝑑/𝑠}\)
An electric fan has blades of length \(30\ \text{cm}\) as measured from the axis of rotation. If the fan is rotating at \(1200\ \text{r.p.m}\), the acceleration of a point on the tip of the blade is about:
1. \(1600\ \text{m/s}^2\)
2. \(4740\ \text{m/s}^2\)
3. \(2370\ \text{m/s}^2\)
4. \(5055\ \text{m/s}^2\)
The angular speed of the second hand in a mechanical watch is:
1. \(\dfrac{\pi}{30}\ \text{rad/s}\)
2. \(2\pi\ \text{rad/s}\)
3. \(\pi\ \text{rad/s}\)
4. \(\dfrac{60}{\pi}\ \text{rad/s}\)