The basic formula for calculating acceleration is:
[tex]a = \frac{v - v_0}{t}[/tex]
a = acceleration
V = final velocity
Vo = initial velocity
t = time
From the above equation, we can derive the formula for calculating the time:
[tex]t = \frac{v-v_0 }{a}[/tex]
Since the man is diving, we can assume that the acceleration due to gravity is 9.8m/s^2.
As such, we can solve for time as follows:
[tex]t = \frac{45m/s - 0 m/s}{9.8 m/s^{2} }[/tex]
[tex]t = \frac{45m/s}{9.8m/s^{2} }[/tex]
[tex]t = 4.59 s[/tex]
The time elapsed is 4.59 seconds.