PLEASE HELP! Two identical satellites orbit the Earth. The distance between the Earth and satellite B is twice the distance between the Earth and satellite A. Which of the following correctly compares the force of Earth's gravity on the satellites?
A. It cannot be determined.
B. The gravitational force acting on satellite B is equal to the gravitational force acting on satellite A.
C. The gravitational force acting on satellite B is less than the gravitational force acting on satellite A.
D. The gravitational force acting on satellite B is larger than the gravitational force acting on satellite A.

The base of a 50-meter tower is at the origin; the base of a 50-meter tree is at (0, 50, 0). the ground is flat and the z-axis points upward. the following parametric equations describe the motion of six projectiles each launched at time t = 0 in seconds. (i) r (t) = (50 + t2)k (ii) r (t) = 2t2 j + 2t2k (iii) r (t) = 50 i + 50 j + (50 − t2)k (iv) r (t) = 2t j + (50 − t2)k (v) r (t) = (50 − 2t) i + 2t j + (50 − t)k (vi) r (t) = t i + t j + tk (a) which projectile is launched from the top of the tower and goes downward? at time t = , the projectile hits the ground at point (x, y, z) = . (b) which projectile hits the top of the tree?