Rotational Motion

Centripetal acceleration always points to the _____ of the circle.

• back

• center

• front

• outer edge

Which of these is a nonexistent force?

• centrifugal

• centripetal

• friction

• gravity

Acceleration is the change in _____ and speed.

• force

• distance

• motion

• velocity

Which is represented by the equation F_net = ma_c ?

• Newton's first law of motion

• Newton's first law of circular motion

• Newton's second law of motion

• Newton's second law of circular motion

A carnival ride has a 3.0-m radius and rotates once every 1.7 s. Find the centripetal acceleration of a rider.

• 11 m/s²

• 41 m/s²

• 82 m/s²

• 98 m/s²

If the radius of the planet's orbit were doubled, what effect would it have on its period of orbit?

• More information is needed to determine the answer.

• It would decrease.

• It would increase.

• It would have no effect.

According to Kepler's laws, the paths of the planets are __________.

• Parabolas

• Ellipses

• Earth-centered

• Circles

The attractive force that exists between all masses is known as the __________.

• gravitational force

• centripetal force

• torque

• normal force

If the mass of a planet near the Sun were doubled, the force of attraction would __________.

• remain constant

• be squared

• be one half as strong

• be doubled

In Newton's equation for the law of universal gravitation, F = Gm₁m₂/r²,

r is __________.

• the distance between the centers of the masses

• a universal constant

• the distance between a planet and the Sun

• the difference in the two masses