Answer:
See the answers below.
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]y=y_{o}+v_{o}*t+0.5*g*t^{2}[/tex]
where:
y = final elevation [m]
yo = initial elevation = 0
vo = initial velocity = 19.6 [m/s]
t = time required [s]
g = gravity acceleration = 9.81 [m/s²]
Now we can replace the different times in the equation above.
For t = 1 [s]
[tex]y=0+(19.6*1)-0.5*9.81*(1^{2} )\\y = 14.7 [m][/tex]
For t = 2 [s]
[tex]y=0+(19.6*2)-0.5*9.81*(2^{2} )\\y = 19.58 [m][/tex]
For t = 3 [s]
[tex]y=0+(19.6*3)-0.5*9.81*(3^{2} )\\y = 14.7 [m][/tex]
For t = 4 [s]
[tex]y=0+(19.6*4)-0.5*9.81*(4^{2} )\\y = -0.08 [m][/tex]
We can see that the sign of gravitational acceleration is negative, since it points in the opposite direction to the motion of the launch.
Note when the time is equal to 4 seconds we see that the distance is 0, ie the tennis ball has reached its maximum height and begins to descend.
