Circular Motion and Rotational Dynamics

An object moves in a circular path at a constant speed. Compare the direction of the object's velocity and acceleration vectors.

• Both vectors point in the same direction

• the vectors point in opposite directions

• the vectors are perpendicular

• the question is meaningless, since the acceleration is zero.

When an object experiences uniform circular motion, the direction of the acceleration is:

• in the same direction as the velocity vector

• in the opposite direction of the velocity vector

• is directed toward the center of the circular path

• is directed away from the center of its circular path

When an object experiences uniform circular motion, the direction of the net force is

• is in the same direction as the motion of the object

• in the opposite direction of the motion of the object

• is directed toward the center of the circular path

• is directed away from the center of the circular path

A pilot executes a vertical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him is

• less than mg, and pointing up

• less than mg, and pointing down

• more than mg, and pointing up

• more than mg, and pointing down

Tags

NGSS.HS-PS2-1

A car goes around a curve of radius r at constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the first?

• four times as big

• twice as big

• one-half as big

• one-fourth as big

Tags

NGSS.HS-PS2-1

Is it possible for an object moving around a circular path to have both centripetal and tangential acceleration?

• No, because then the path would not be a circle.

• No, an object can only have one or the other at any given time

• Yes, this is possible is the speed is constant.

• Yes, this is possible if the speed is changing.

An object moves with constant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the object?

• zero

• 0.17 m/s²

• 5.0 m/s²

• 6.0 m/s²

Tags

NGSS.HS-PS2-1

A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal acceleration?

• 0.050 m/s²

• 1.35 m/s²

• 48.0 m/s²

• 198 m/s²

Tags

NGSS.HS-PS2-1

How many revolutions per minute must a circular, rotating space station of radius 1000 m rotate to produce an artificial gravity of 9.80 m/s²?

• 0.65 rpm

• 0.75 rpm

• 0.85 rpm

• 0.95 rpm

Tags

NGSS.HS-PS2-1

A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the sting can withstand is 350 N. What is the maximum speed of the mass if the string is not to break?

• 700 m/s

• 26 m/s

• 19 m/s

• 13 m/s

Tags

NGSS.HS-PS2-1