Why Gravity Is Inverse Square Law And Not Inverse Cube Physic Problems Who Can Get It Correct The Fastest (5 Points, Mutiple Choice)?

Physic problems who can get it correct the fastest (5 points, mutiple choice)? - why gravity is inverse square law and not inverse cube

1. A car pulling a trailer, moves on a flat road at constant speed. The strength of the car on the trailer
A) equals the force the trailer exerts on the car
B) equal to the pull of Wight
C) greater than the force the trailer exerts on the car
D) carries less than the force of the trailer on the car

2.A 2 kg mass is moving 10m / s collides with sticks and fricctionless surface. Velocity of the total mass after the collision A) to 2 m / s B) 4 m / s C) 6 m / s D) 8 m / s

3. Two Ping - Pong traded on the other side by the gravitational field. The reason is to roll the two balls, is not together
A) that diminish the forces
B) The acceleration of gravity of both is the same
C),no unbalanced force acting on a ball
D) None of these answers

4. (critical question) If the radius of the orbit of a planet around the sun, the cube, then place by the length of the planet divided
A) the result is the reverse of the third law of Kepler
B) is the result of the centripetal force on the planet
C) the same number is always obtained
D) will be a different number obtained for each planet.