Question

from the edge of the top of the building with the height of 30 m erica kicks a soccer ball with a velocity of 12 m/s horizontally what is the velocity of the soccer ball when it strikes the ground

Answer 1

The vertical component of velocity:

$$v_y=\sqrt{2gh}=24.2\text{ m/s}.$$

The horizontal component does not change if we ignore air resistance. So, the velocity before hitting the ground can be found by the Pythagorean theorem:

$$v=\sqrt{v_x^2+v_y^2}=27\text{ m/s}.$$