Answer:
3.25 seconds
Explanation:
It is given that,
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :

Where
s is the height in feet
For the given condition, the equation becomes:

When it hits the ground, h = 0
i.e.

It is a quadratic equation, we find the value of t,
t = 3.25 seconds and t = -0.134 s
Neglecting negative value
Hence, for 3.25 seconds the baseball is in the air before it hits the ground.
Do swimming which make Newtons Third Law
The word displacement implies that an object has moved, or has been displaced. Displacement is defined to be the change in position of an object.
Displacement is defined as the act of moving someone or something from one position to another or the measurement of the volume replaced by something else
C. coil suspended by bearings.
<span>but im not 100% sure</span>