Circular Motion

A ball on a string is travelling in circular motion. Which vector represents the centripetal force?

• The green vector because it points towards the center of the circular path
• The blue vector because it shows the direction of the object's inertia
• The green vector because it shows the path of the ball
• The blue vector because this is the way the ball will move when it is released.

Which represents the acceleration of the ball?

• A
• B
• C
• D

Where is the net force when the rollercoaster is at the top of the loop?

• Towards the sky
• Towards the Right
• Towards the left
• Towards the ground

A type of circular motion when an object turns about an internal axis...

• rotation

• revolution

• tangential speed

• velocity

A type of circular motion that occurs when an object turns around an external axis.

• rotation

• revolution

• tangential speed

• velocity

The distance per unit of time of something moving along a circular path is called...

• linear speed

• tangential speed

• rotational speed

• centripetal force

Rotational speed (also called angular speed) is ...

• distance per unit time in a circle

• number of rotations

• number of rotations per unit of time

• distance between the midpoint and the outer edge

what is the relationship between tangential speed (v), radial distance (r) and rotational speed (w)?

• w = rv

• r = wv

• v = wr

• v = w/r

Compare the rotational velocity of 2 children on a merry-go-round. One is at the edge, the other is midway between the middle and the edge.

• Rotational velocity is more for child on the edge

• Rotational velocity is more for child in the middle

• Rotational velocity is the same for both

• There is no way to compare the rotational velocities

Railroad train wheels have a tapered shape because

• On a curve, the outer wheels must travel faster

• the trains will fall off the tracks without them

• on a curve the inner wheel must travel faster

• trains don't have tapered wheels