A rock (m= 2kg) is shot up vertically at the same time that a ball (m= 0.5kg) is projected horizontally. If both start from the
same height: A. the rock and ball will reach the ground at the same time. B. the rock will reach the ground first.
C. the ball will reach the ground first.
D. the rock and ball will collide in the air before reaching the ground.
Can you explain why the answer is C?
The correct option is C. the ball will reach the ground first.
The ball will reach the ground first since the mass of each object does not affect the rate of fall, both are subject to the same gravitational acceleration 9.81 m / s2. The rock in its vertical movement invests a time that the ball is not released horizontally, so that time of vertical flight of the rock plus the extra height it will have will reach the ground after the rock. Regardless of the friction of the air, it will be different in both objects.
There are a couple of things that the swimmer in the video did in order to prepare for the energy demands he was about to place on his body: 1. he gained 16 pounds of body fat in order to have his body ready for that ordeal 2. he prepared his mind mentally for what was about to happen 3. he went through a lot of physical training