Question

a football is thrown into the air at an upward angle, and it eventually hits the ground. which describes its motion correctly? assume there is no air resistance. (1 point) in the vertical direction it moves up at a constant speed, reverses direction, then falls down at a constant speed until it hits the ground. in the horizontal direction it slows down until it hits the ground. in the vertical direction it moves up quickly, slows down, reverses direction, then speeds up until it hits the ground. in the horizontal direction it moves at the same speed. in the vertical direction it moves up quickly, slows down, reverses direction, then speeds up until it hits the ground. in the horizontal direction it slows down until it hits the ground. in the vertical direction it moves up at a constant speed, reverses direction, then falls down at a constant speed until it hits the ground. in the horizontal direction it moves at the same speed.

Explanation:

In the vertical direction, the football is under the influence of gravity. Gravity causes an acceleration of approximately $g = 9.8\ m/s^{2}$ down - ward. So it moves up with its vertical velocity decreasing (slows down), reaches a maximum height where the vertical velocity is 0, then reverses direction and speeds up as it falls. In the horizontal direction, since there is no air resistance and no horizontal force acting on it (assuming no other external horizontal forces), according to Newton's first law, it moves at a constant speed.

Answer:

B. In the vertical direction it moves up quickly, slows down, reverses direction, then speeds up until it hits the ground. In the horizontal direction it moves at the same speed.