Circular Motion and Gravitation

Two massive objects placed a distance d apart from each other attract each other with a gravitational force. If they are rearranged so that they are now d/3 apart, the force is now ---.

• 9× what it was

• 1/9× what it was

• 3× what it was

• 1/3× what it was

• 6× what it was

Tags

NGSS.MS-PS2-4

Complete the following statement: The farther away two planets are the _______ the gravitational force between them.

• more

• same

• dosen't matter

• less

Calculate the amount of centripetal force it takes for a softball pitcher to rotate a ball with a speed of 3.0 m/s if the ball weighs 0.12 kg and her arm is 0.65 meters long.

• 0.83 N

• 1.2 N

• 0.55 N

• 1.7 N

Tags

NGSS.MS-PS2-2

A 30-kg child is on a merry-go-round which has a radius of 1.5 m. Her sister spins her at a speed of 9.0 m/s. How big is the centripetal force acting on the child?

• 180 N

• 405 N

• 1,620 N

• 54 N

Tags

NGSS.MS-PS2-2

You are moving a ball in a circle using 72 N of centripetal force. What would the force be if you doubled the velocity of the circle?

• 244 N

• 288 N

• 36 N

• 72 N

Tags

NGSS.HS-PS2-1

The velocity is always _____ to the line of a circle. 

• outwards

• towards the center

• tangent

• faster

A particle is moving in a circular path of radius r.

The displacement after half a circle would be:

• (a) Zero

• (b) πr

• (c) 2r

• (d) 2πr

What's the centripetal acceleration of a 0.20-kg yoyo spun in a circle with a radius of 0.70 meters at a speed of 3.0 m/s?

• 8.23 m/s²

• 10.5 m/s²

• 12.9 m/s²

• 2.6 m/s²

Tags

NGSS.HS-PS2-1

A stopper at the end of a string is spun in a circle. If the radius of the string is 0.30 m, and the stopper makes one complete circle in 0.20 s, what is the speed of the stopper?

• 9.4 m/s

• 1.5 m/s

• 11.7 m/s

• 3.5 m/s

Tags

NGSS.MS-PS2-2

A test car moves at a constant speed around a circular track. If the car is 48.2 m from the track's center and has a centripetal acceleration of 8.05 m/s², what is the car's tangential speed?

• 19.7 m/s

• 1.34 m/s

• 0.408 m/s

• 388 m/s

Tags

NGSS.MS-PS3-1