Physics question

Question

A ball is thrown upward at time t=0 from the ground with an initial velocity of 18 m/s (~ 40 mph). Assume that g = 10 m/s2. What is the greatest height (in meters) reached by the ball?

Answer 1

h(t) = -gt²/2 + v₀t + h₀

 

g = 10 m/s²

v₀ = 18 m/s

h₀ = 0

 

h(t) = -5t² + 18t

 

Maximum height occurs when the speed is instantaneously zero.

 

v(t) = v₀ - gt = 18 - 10t

 

18 - 10t = 0

 

Solve for t, and then plug this value of t into h(t) to get h_max.  You should be able to finish from here.