Circular Motion

Practice Problem 1: In the equation for centripetal force, which expression represents the centripetal acceleration of the object?

Tags

NGSS.HS-PS2-1

Practice Problem 2: Rahul wants to change the motion map shown so that it shows uniform circular motion. What change should Rahul make?

• He should change the length of each vector that points toward the center so that it is the same length as the vector pointing tangent to the circle at that point.

• He should change the lengths of the vectors that point tangent to the circle so that each is the same length.

• He should change the direction of the vectors that are tangent to the circle so that each points away from the center of the circle.

• He should change the direction of the vectors that are tangent to the circle so that each points toward the center of the circle.

Practice Problem 3: An object is represented by the dot on the motion map. Which object is most likely represented by the dot?

• a car driving over the top of a hill

• a ball on a string that stopped at the top of a vertical loop

• a roller coaster car at the top of a vertical loop of track

• a bug on the top of a rolling hula hoop

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

Practice Problem 4: An object moving in a circle is represented by the motion map. Based on the map, at which point is the object accelerating toward the right?

• W

• X

• Y

• Z

Tags

NGSS.HS-PS2-1

What is the direction of the centripetal force when applied to an object?

• the direction opposite to the object’s velocity

• the same direction as the object’s velocity

• perpendicular to an object’s motion

• parallel with an object’s motion

How does a centripetal force cause circular motion?

• It acts at a right angle to the object’s motion and causes the object to constantly change direction.

• It acts at a right angle to the object’s motion and causes the object to constantly change speed.

• It acts in the direction of the object’s motion and causes the object to constantly change direction.

• It acts in the direction of the object’s motion and causes the object to constantly change speed.

What must be true of a force that causes an object to move in a circular motion?

• It acts parallel to the velocity and is directed toward the center of the circle.

• It acts parallel to the velocity and is directed away from the center of the circle.

• It acts perpendicular to the velocity and is directed toward the center of the circle.

• It acts perpendicular to the velocity and is directed away from the center of the circle.

Johanna makes the table below to organize her notes about centripetal forces. Which type of force should she place in the cell marked X?

• tension

• gravity

• friction

• normal

Tags

NGSS.MS-ESS1-2

A centripetal force causes circular motion because it accelerates an object

• toward the center of a circle, which changes the direction of motion but not the speed.

• toward the center of a circle, which changes the speed of motion but not the direction.

• along the edge of a circle, which changes the direction of motion but not the speed.

• along the edge of a circle, which changes the speed of motion but not the direction.

How do inertia and centripetal force combine to keep an object moving in circular motion?

• Centripetal force acts toward the center of the circle to overcome inertia, which acts away from the center.

• Inertia acts toward the center of the circle to overcome centripetal force, which acts away from the center.

• Centripetal force acts toward the center of the circle, and inertia keeps the object moving forward.

• Inertia acts toward the center of the circle, and centripetal force keeps the object moving forward.