Circular Motion

A body moves in a horizontal circle with constant speed. Which of the following is true?

• The velocity and acceleration are both constant

• The acceleration is directed tangentially

• The net force is zero

• The velocity changes direction but not magnitude

Which pair correctly shows the unit of angular velocity?

• m/s

• m/s²

• rad/s 

• rad/s²

The relation between linear speed v and angular velocity (omega) is:

• v = w/ r

•  v = r \w

• v = rw

• v = w^2 . r

Centripetal acceleration always points:

• Tangent to the path

• In the direction of motion

• Perpendicular to velocity

• Towards the center of the circle

Which of the following does not affect the centripetal force required for circular motion?

Tip: Always identify the quantity which the force is independent of, from its own expression.

• Radius of the circle

• Mass of the object

•  Linear speed of the object

• Gravitational potential energy

A disk rotates at 2 revolutions per second. What is the angular velocity?

• 2 pi rad/s

• 4 pi rad/s

• 1 pi rad/s

• 6.28 rad/s

A car going around a bend slows down. What type of acceleration does it experience?

• Centripetal only

• Tangential only

• Both tangential and centripetal

• none

Which formula correctly calculates arc length s of a circular path?

•  s = r \w

• s = r. theta

•  s = theta / r

•  s = r \theta

Convert 180^ to radians.

• pi /2

• pi

• 2 pi

• pi /4

convert 3 pi/4 rad into degrees

• 135

• 90

• 180

• 270