Rotational Motion

Where will be the centre of mass of a uniform rod lies ?

• At its end

• At its middle point

• At its centre of its cross sectional area

• Depends upon its material

Where the center of mass of a circle lies?

• At its centre

• Anywhere on its radius

• Anywhere on its circumference

• Anywhere on its diameter

The relation between linear velocity and angular velocity

• r = v⍵

• ⍵ = vr

• v = r⍵

• a = v⍵

The unit of angular velocity is

• m/s

• m/s²

• rad/s

• rad/s²

A grindstone spinning at the rate of 8.3 rev/s has what approximate angular speed?

• 3.2 rad/s

• 26 rad/s

• 52 rad/s

• 81 rad/s

The figure shows scale drawings of four objects, each of the same mass and uniform thickness, with the mass distributed uniformly. Which one has the greatest moment of inertia when rotated about an axis perpendicular to the plane of the drawing at point P?

• A
• B
• C
• D

Two uniform solid balls, one of radius R and mass M, the other of radius 2R and mass 8M, roll down a high incline. They start together from rest at the top of the incline. Which one will reach the bottom of the incline first?

• The small sphere arrives first.
• The large sphere arrives first.
• Both reach the bottom at the same time.

When an object is experiencing a net torque

• it is in dynamic equilibrium.
• it is in static equilibrium.
• it is rotating.
• it is translating.

Calculate the torque produced by 75- N perpendicular force at the end of a 0.20 m long wrench.

• 15 Nm

• 1.5 Nm

• 15.0 Nm

• 16 Nm

What would happen to the length of one day if Earth's moment of inertia were to increase?

• The day would be longer.
• The day would be shorter.
• The day would stay the same.