Unit 6 Test Review: Circular Motion

Kepler's 2nd Law of Planetary Motion states what?

• planets maintain constant speed around sun

• planets maintain constant acceleration around sun

• the speed of a planet is greatest when closest to the sun

• the area swept out by the orbit per time unit keeps changing

Kepler's 1st law states what?

• the orbits of planets are elliptical

• speed of planet's orbit varies depending on which part of the ellipse it is occupying.

• the square of the ratio of the periods of any two planets revolving around the sun is equal to the cube of the ratio of their average distance from the sun

• objects attract other objects with a force that is directly proportional to the produce of their masses

What would happen to force of gravity between two planets if the distance between them doubled?

• it will increase 2x

• it will increase 4x

• it will decrease 2x

• it will decrease 4x

Which of the following is a field force?

• contact force

• normal force

• gravitational force

• frictional force

an object is tied to a string and swung in a circle. Which of the following forces would be the centripetal force?

• friction

• inertia

• gravity

• tension

A tiger is moving at a speed of 30 m/s around a bend with radius 15m. What is the tiger's centripetal acceleration?

• 2 m/s2

• 15 m/s2

• 60 m/s2

• 80 m/s2

A dog moving the speed of 12 m/s rounds a bend with radius 18 m. What is the centripetal force acting on the dog if the dog's mass is 25 kg?

• 3 N

• 8 N

• 17 N

• 200 N

What would be the gravity on the surface of a planet with a mass of 8.35 x 10^22 kg and a radius of 1600km?

• 2.17 m/s2

• 2170000 m/s2

• 9.8 m/s2

• 4.3 m/s2

What causes the feeling of being thrown off while on a rotating object?

• centripetal force pushing you away

• tangential speed pushing you away

• newton's 1st law of inertia in action

• centripetal acceleration pulling you in

What is the gravitational force between two cans of coke which are 65 cm apart? Each can has mass of 680g.

• 2.3 x 10^-12 N

• 15.7 x 10^-5 N

• 7.3 x 10^-11 N

• 7.3 x 10^-5 N