AP Physics Question

Question

A boy throws a stone straight upward with an initial speed of 15 m/s. What maximum height will the stone reach before falling back down?

Answer 1

The maximum height is reached when the y direction velocity is zero. Here is the formula we will use

Vf^2 = Vi^2 + 2ad

Known a = -9.8 m/s^2, Vf= 0, Vi = 15m/s solving for d (or height here)

0=(15m/s)^2 + 2(-9.8 m/s^2) (d)

0 = 225 m^2/s^2 - (19.6 m/s^2) d

d = 225/19.6 m

d = 11.5 m