Question

A ball is thrown horizontally from a 18m -high building with a speed of 9.0m/s .

How far from the base of the building does the ball hit the ground?

Please show all work and equations thank you!

Answer 1

o find out how far something travels in the x direction, we need to know how long it is going for. The only way to do this is to figure out how long it will take to drop off a 18m building.
For that first step, to find the time, we will use the kinematics equation:
h = .5gt^2 << you had that part, good job
Using algebra, we get that:
t = ?((2h) / g)
Plug in our values:
t = ?(18*2 / 10) = ?1.8*2 = 1.9s (roughly)

Now, with 1.9 seconds with which to fall, we use the equation:
d = vt
Plug in our values:
d = (9)(1.9) = 17.1m