Why does Mars exhibit retrograde motion in the sky? Mars orbits the Sun in the opposite direction as the Earth.

As Mars overtakes and passes the Earth in its orbit, Mars appears to move backwards.

As the Earth overtakes and passes Mars in its orbit, Mars then appears to move backwards.

When Mars and the Earth are on opposite sides of the Sun, it can no longer be seen at night.

What is the reason of this question?

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.