Question

A ball is thrown in the air from the top of a building. Its height, in meters above ground, as a function of time, in seconds, is given by h(t)=−4.9t2+21t+6. How long does it take to reach maximum height?

Answer 1

Answer:

we have to find the derivate of that function which is: -4.9*2t +21 and to find the maximum height this derivate should be equal to 0

-9.8t+21=0 so

t=21/9.8=2.14