Answer:
u = 7.74 m/s and t = 1.82 s
Step-by-step explanation:
Given that,
Harold threw a baseball 3 meters.
Harold is 2 meters tall.
The vertical distance = 3m
The final velocity at the maximum height is 0.
Let u is the initial velocity of the baseball. Using the first equation of motion to find it as follows :
![v^2-u^2=2as](https://img.qammunity.org/2021/formulas/physics/high-school/62imstr5dn6q95b14ng9iu55jgj34qnto2.png)
Here, a = -g
![v^2-u^2=-2gs\\\\u=√(2gs) \\\\=√(2* 10* 3) \\\\=7.74\ m/s](https://img.qammunity.org/2021/formulas/physics/high-school/mjgq2lg0lj0cun1hys9pn2h1r373eegvwb.png)
He has thrown it with the speed of 7.74 m/s
Let t is the time taken by the ball to fall on the ground.
Harold is 2 meters tall. Using second equation of motion to find it.
u = -7.74 (as downward direction is taken as positive)
![s=ut+(1)/(2)at^2\\\\2=-7.74t+5t^2\\\\t=1.82\ s](https://img.qammunity.org/2021/formulas/physics/high-school/gon2cts46idpsc2y9vzgmc8hrrh3aoqg99.png)
Hence, this is the required solution.