AP Circular Motion

Question A moon of mass 1×1020kg is in a circular orbit around a planet. The planet exerts a gravitational force of 2×1021N on the moon. The centripetal acceleration of the moon is most nearly Responses

10 m/s^2

A student rides a bicycle in a circle at a constant speed and constant radius. A force diagram for the student-bicycle system is shown in the figure above. The value for each force is shown in the figure. What is the acceleration of the student-bicycle system?

0.2 m/s^2

During an experiment, an object is placed on a disk that rotates about an axle through its center, as shown in Figure 1. The block is a distance R=0.10 m from the center and rotates with a constant tangential speed of 0.60 ��. A free body diagram of the forces exerted on the block is shown in Figure 2 with an unknown force of friction. What is the force of friction exerted on the block?

0.72N

A ball is attached to one end of a string such that the ball travels in a vertical circular path near Earth's surface. The force diagram of the ball at its lowest point in the circular path is shown above. What is the net centripetal force exerted on the ball? Responses 10⁢ � 10 newtons

15N

A block of known mass M is on a disk that rotates about its center, as shown above. The block travels with the disk and does not slip. The block travels at a constant tangential speed V when at a distance R from the center with a centripetal force of magnitude F exerted on it. The tangential speed V of the block represents the maximum speed of the block without the block slipping on the disk. Which of the following statements about other quantities that might be determined is correct? Select two

A. The centripetal force exerted on the block at a larger radius can be determined, since F=mv^2/R can be applied using the given known quantities. B.The centripetal acceleration of the block can be determined, since ac=v^2/r since the block's tangential speed is known and the radius is known.

An astronaut with mass �� is within a satellite that orbits Earth at a height � above its surface. Earth has a mass �� and radius ��. Which of the following is a correct expression for the gravitational force exerted on the astronaut by Earth?

Fg= G MeMa/(RE+H)^2

The figure above shows the position of a moon that orbits a planet in an elliptical path. Two specific locations of the moon, position A and position B, are labeled. Question As the moon orbits the planet from position A to position B, is the magnitude of the planet's force due to gravity exerted on the moon constant? Why or why not?

No, because the moon's distance from the planet is always changing.

A moon orbits an isolated planet in deep space. Which of the following forces that the planet exerts on the moon can be considered as negligible?

The electric Force

The figure above shows the position of a moon that orbits a planet in an elliptical path. Two specific locations of the moon, position A and position B, are labeled. Question In what direction is the net force exerted on the moon?

Toward the center of the ellipse

A satellite of mass � orbits a moon of mass � in uniform circular motion with a constant tangential speed of �. Question The gravitational field strength at a distance R from the center of moon is ��. The satellite is moved to a new circular orbit that is 2� from the center of the moon. What is the gravitational field strength of the moon at this new distance?

gR/4