According to Newton’s third law, the force on the smaller moon due to the larger earth is a. greater in magnitude and antiparallel to the force in the earth due the moon. b. equal in magnitude and parallel to the force on the earth due to the moon. c. equal in magnitude but antiparallel to the force on the earth due to the moon. d. smaller in magnitude and antiparallel to the force on the earth due to the moon.

The orbit of a planet around the sun is : O A. hyperbolic. O B. parabolic. OC. elliptic. OD. circular.

5. Determine the source of centripetal force in the following examples. a. Earth orbiting around the sun. b. Car moving along a circular track. c. Bucket attached to a rope, spun in a horizontal circle.

choose all that apply to centripetal force.   A. twice the radius needs half the centripetal force. x   B. Gravitational and electrical forces can produce centripetal forces.   C. Twice the speed needs four times the centripetal force.   D. Centripetal force depends on the mass, tangential speed and radius of the curvature.   E. Centripetal force depends on tangential spreed and radius of curvature .   F. Measured in the units of N or kg m/s^2   G. Any type of force directed towards a fixed center. I chose everything except answer E and got it wrong.

010: A new planet (tentatively named "Melmac") is found in a circular orbit with a period of 571 years. The sun has a mass of 1.9891x1030 kg. How far away is the planet in Astronomical Units (AU) ? Note: An A.U. is 1.496x1011 m.

14 Four 9.5-kg spheres are located at the corners of a square of side 0.80 m. Calculate the magnitude and direction of the gravitational force exerted on one sphere by the other three.   A. 1.08x10-8 N   B. 1.80x10-8 N   C. 1.21x10-8 N   D. 1.12x10-8 N   E. None of the above

What would be the mass of a 60-kg astronaut on a planet with the same density as Earth and having twice Earth's radius? a.240 kg  b. 120 kg  c. 60 kg                                   d. 30 kg

1. Determine the force of gravitational attraction between a 67-kg father and his 12.8-kg son if they are separated at a distance of 5.29 x 105 m from each other. a. 1.02 x 1029 N b. 1.44 x 10-5 N c. 1.01 x 10-7 N d. 2.04 x 10-19 N 2. Two objects with equal masses of 1 kg each are separated by a distance of 1 m. The gravitational force between the objects is: a. Slightly less than G b. Slightly greater than G c. Equal to G d. Half as much as G

A distant star has a single planet circling it in a circular orbit of radius 8.47 x 10¹1 m. The period of the planet's motion about the star is 668 days. What is the mass of the star? The