Question

A batter hits a baseball 4 feet above the ground with an upward velocity of 59 feet per second. The function h(t) = -16t^2 + 49t + 4 gives the height h (in feet) of the baseball after t seconds. How long is the ball in the air if a player on the other team catches the ball 7 feet above the ground?

Answer 1

3 seconds

Explanation:

when h=7 ft

-16t²+49t+4=7

-16t²+49t-3=0

16t²-49t+3=0

16t^2-48t-t+3=0

16t(t-3)-1(t-3)=0

(t-3)(16t-1)=0

t=3,t=1/16

t=1/16 seconds is the time when it just started.

so reqd. time=3 seconds.