Answer:
v = 42.28 m/s
Step-by-step explanation:
It is given that,
The horizontal speed of a baseball,
![u_x=42\ m/s](https://img.qammunity.org/2021/formulas/physics/high-school/bujjor9mntwspvaudm31u8stxhps5y3qhf.png)
The pitcher throws the baseball from a height of 1.25 meters, h = 1.25 m
Firstly finding t i.e. the stone takes to reach the ground. Using second equation of motion as follows :
![d=ut+(1)/(2)at^2](https://img.qammunity.org/2021/formulas/physics/college/v525it91ua1qp9pi8p6scw2ez8eyqs85j6.png)
a = -g and u = 0
![d=-(1)/(2)gt^2\\\\t=\sqrt{(-2d)/(g)} \\\\t=\sqrt{(-2* 1.25)/(9.8)} \\\\t=0.5\ s](https://img.qammunity.org/2021/formulas/physics/high-school/usow3l5a4gs087kxcxi9c2wk5cevc6whvu.png)
Vertical component of the velocity is :
![v_y=gt\\\\v_y=9.8* 0.5\\\\v_y=4.9\ m/s](https://img.qammunity.org/2021/formulas/physics/high-school/gwp93qh1qb9v5gt85vwimr4wkw2x64tckq.png)
Resultant velocity,
![v=√(v_x^2+v_y^2) \\\\v=√(42^2+4.9^2) \\\\v=42.28\ m/s](https://img.qammunity.org/2021/formulas/physics/high-school/s9q9v2zt2fhv3c46dpnpu65jqyz3hqv819.png)
So, the resultant velocity of the ball before it hits the ground is 42.28 m/s.