Question

A ball is thrown horizontally at 10.0m/s. It is in the air for 5.00s.
a) How far does it fall vertically?
b) How far does it travel horizontally?
c) How fast is it moving vertically when it hits the ground?
d) what is its speed when it hits the ground?

Answer 1

a) Since it has no initial velocity in the vertical direction, it's just like dropping something that takes 5 sec. to hit the ground. How far will it go? Look at your projectile motion equations for one the gives distance that is determined by acceleration (gravity) and time.
b) The horizontal velocity remains constant, so how far can it go in 5 seconds? Again, look at your equations for one that gives distance in the x direction, determined from velocity and time.
c) The initial velocity in the vertical direction is 0. You know the time and that gravity is making it accelerate. So, look for an equation that gives final velocity as a result of acceleration (gravity) and time.
d) You are given the horizontal velocity and you just calculated the vertical velocity. Use the Pythagorian theorum V^2 = Vx^2 + Vy^2 to determine the final speed.