CIRCULAR MOTION

Question 1

The turntable rotates around its axis while a ladybug sitting at its edge revolves around the same axis. Which part of the turntable moves faster—the outer part where the ladybug sits or a part near the orange center?

Answer 1

The linear speed is greater on the outer edge of a rotating object than it is closer to the axis.
In rotational speed, all parts of the rigid turntable rotate about the axis in the same amount of time.

Question 2

Tangential speed is directly proportional to the

Answer 2

rotational speed and the
radial distance from the axis of rotation.

Question 3

What happens As you move away from the centre (of the circle)

And move out twice as far from the centre

Answer 3

your tangential speed increases while your rotational speed stays the same.

Move out twice as far from the centre, and you have twice the tangential speed.

Question 4

At an amusement park, you and a friend sit on a large rotating disk. You sit at the edge and have a rotational speed of 4
RPM and a linear speed of 6 m/s. Your friend sits halfway to the center.

What is her rotational speed?

What is her linear speed?

Answer 4

Her rotational speed is also 4 RPM, and her linear speed is 3 m/s.

Question 5

What happens if you Fasten a pair of cups together at their wide ends and roll the pair along a pair of parallel tracks.

Answer 5

The cups will remain on the track.
and they will center themselves whenever they roll off center (2)

Question 6

What happens when a train rounds a curve,

Answer 6

the wheels have different linear speeds for the same rotational speed.

Question 7

Train wheels ride on a pair of tracks. For straight-line motion, both tracks are the same length. But which track is longer for a curve, the one on the outside or the one on the inside of the curve?

Answer 7

The outer track is longer—just as a circle with a greater radius has a greater circumference.

Question 8

The centripetal force on an object depends on the object’s

Answer 8

tangential speed, its mass, and the radius
of its circular path.

Question 9

Any object moving in a circle undergoes an
acceleration that is directed to the center of the circle is a

Answer 9

centripetal acceleration.(2)

Question 10

What keeps a vehicle in a circular path

Answer 10

Centripetal force (2)

Question 11

is attributed not to any real force but to inertia—the tendency of the moving body to follow a straight-line path.

Answer 11

centrifugal-force effect

Question 12

What causes the “centrifugal-force effect”?

Answer 12

is an effect of rotation. It is not part of an interaction and therefore it cannot be a true force.