Question

A ball is thrown straight up at 20.0 m/s. How fast is the ball moving after 2.00 s?

Answer 1

∆y = vit + 1/2at²
∆y = (20)(2) + 1/2(-9.8)(2)²
∆y = 30.2 m

Answer 2

whoops, thought it said distance

vf = vi + at
vf = (20) + (-9.8)(2)
vf = 0.4 m/s

Answer 3

And that one with the truck and the car bothered you ?

Answer 4

I bet her class uses g = -10 m/s^2 so it came out zero.