1. ## Derivative Problem

The height of a soccer ball after it is kicked into the air is given by h(t)=-4.9t^2+3.5t+1, where h is the height in metres and t is the time in seconds

a)determine the rate of change of the height of the soccer ball at time t.
-9.8x+3.5 didnt have problem with that

b) Determine the rate of change of the height of the soccer ball at 0.5s
-9.8(0.5)+3.5= -1.4m/s no problem with that

c) When does the ball momentarily stop?
What is the height of the ball at this time?

...... have no clue......

2. The ball momentarily stops when the velocity is 0. So set h'(t) = 0 and solve for t to find the time when the ball stops. Then plug the value you got for t into h(t) to get the height.