AP Circular Motion and Gravitation

Calculate the force of Earth's gravity on a spacecraft 12,800 km (2 Earth radii) above the Earth's surface if its mass is 1350 kg. The mass of the Earth is 5.97 x 10^24 kg.

• 1464 N

• 1.46 x 10^8 N

• 1.46 x 10^-2 N

• 14600 N

Two satellites are in circular orbit around Earth. Satellite A has speed v. Satellite B has an orbital radius nine times that of satellite A. What is the speed of satellite B?

• v/3

• 3v

• 9v

• v/9

A horizontal force of 210 N is exerted on a 2.0 kg discus as it rotates uniformly in a horizontal circle at a radius of 0.90 m. What is the speed of the discus?

• 9.72 m/s

• 6.2 m/s

• 55.8 m/s

• 30.7 m/s

How does the acceleration due to gravity change if you were to visit a planet with four times the mass of Earth and half the radius?

• Acceleration would be 2g

• Acceleration would be 16g

• Acceleration would be 1/2 g

• Acceleration would be 4g

Which TWO forces must be equal for a stable orbit?

• Gravitational force

• Frictional force

• Inertia

• Centripetal force

If an object takes 4.1 seconds to hit the ground from a 50 meter height, what is the acceleration due to gravity on that planet?

• 5.95 m/s/s

• 24.39 m/s/s

• 6.11 m/s/s

• 2.16 m/s/s

An object with mass M is moving in a uniform circular motion at a speed v with a radius r. If the mass were to be increased to 3M, how would the centripetal force change?

• It would increase by a factor of 3.

• It would increase by a factor of 9.

• It would decrease by a factor of 3.

• It would decrease by a factor of 9.

Mrs. Scarborough is riding a roller coaster. If the mass of her and the car she is riding is 1200 kg and she experiences an acceleration of 10.2 m/s/s at the bottom of the loop, what is her normal force at the bottom?

• 2400 N

• 480 N

• 12240 N

• 11760 N

What is the force required to swing a 0.05 kg washer in a circular radius of 0.8 meters at 4.00 revolutions per second?

• 25 N

• 1.26 N

• 505 N

• 404 N

A moon has a near circular orbit around a planet. If the planet has a radius of 182,000 km and the moon has a period of 3 days, what is the centripetal acceleration?

• 0.107 m/s/s

• 107 m/s/s

• 10.7 m/s/s

• 0.00242 m/s/s