Kinematics of uniform circular motion

Convert 30^o into radians.

• 0.52 rad

• 3.7 rad

• 94 rad

• 1700 rad

Convert 1.0 radians into degrees.

• 30^o

• 57^o

• 167^o

• 230^o

When a body moves with a constant speed along a circle,

• no work is done on it.

• no force acts on the body.

• its velocity remains constant.

• no acceleration is produced in the body.

If the body is moving in a circle of radius r with a constant speed v, its angular velocity is

• v² / r

• vr

• v / r

• r / v

The planet Mercury takes 88 days to orbit once round the Sun. Calculate its angular displacement in radians during a time interval of 1 day.

• 0.012 rad

• 0.036 rad

• 0.071 rad

• 3.14 rad

An aeroplane is circling in the sky at a speed of 150 m s⁻¹. The aeroplane describes a circle of radius 20 km. For a passenger of mass 80 kg inside this aeroplane, determine her angular velocity.

• 7.5 rad s⁻¹

• 10.7 rad s⁻¹

• 3.0x10³ rad s⁻¹

• 7.5x10⁵ rad s⁻¹

An object completes 10 revolutions in a time of 8.2 s. Calculate the time taken for one revolution.

• 0.82 s

• 8.2 s

• 82 s

• 820 s

An object completes 10 revolutions in a time of 8.2 s. Calculate the frequency.

• 0.82 Hz

• 1.22 Hz

• 2.58 Hz

• 8.20 Hz

Define 1 radian.

• Angle swept out by a line passing through any point on the body and intersecting the axis of rotation perpendicularly.

• Net force required to keep an object moving on a circular path.

• angle swept out by the radius per unit time.

• Angle subtended at the centre of a circle by an arc of length equal to the radius of the circle.

State the meaning of angular speed.

• Angle swept out by a line passing through any point on the body and intersecting the axis of rotation perpendicularly.

• Net force required to keep an object moving on a circular path.

• Angle swept out by the radius per unit time.

• Angle subtended at the centre of a circle by an arc of length equal to the radius of the circle.