Uniform Circular Motion

The motion of the Moon around the Earth is an example of ____________.

• uniform action

• projectile motion

• rectilinear motion

• circular motion

A car travels in a circle at constant speed. Which of the following is TRUE about the net force on the car?

• zero because the car is not accelerating.

• directed towards the direction of travel

• directed towards the center of the circle.

• none of the above.

What can be said of an object in uniform circular motion?

• It has a constant velocity.

• It is an example of Newton's First Law in the absence of a force.

• It has a constant tangential speed.

• none of the choices given

The rider of a Ferris wheel moves at a rate of 0.18 m/s^2.

Which of the following is a unit of acceleration?

• m/s

• m/s²

• m.s²

• m/s.s

What is the most direct cause of a car's centripetal acceleration as it rounds a curve?

• The force of the steering wheel

• The weight of the car.

• The normal force exerted by the road.

• The friction between the tires and the road.

A car rounds a 200-m radius curve at 10 m/s. Calculate the centripetal acceleration of the car.

An object A travelling with speed v and following a circular path of radius R has a centripetal acceleration of a. A second object B moving with twice the speed of the first object around a circular path of radius, 2R has a centripetal acceleration that is

• the same as object A

• twice that of object A

• Four times as much as object A

• 1/2 as much as object A

The centripetal acceleration, ac also points toward the center of the circle and has a magnitude given by

• $a\ =\frac{v^2}{R}$

• $a\ =\frac{mv^2}{R}$

• $a\ =Fm$

• $a\ =\ \frac{v^{ }}{R}$

A 20,000 N car travelling at 12 m/s rounds a curve of radius 125 m. Its The centripetal force acting on the car is