Question

11. PLEASE HELP ME

A ball is thrown into the air with an upward velocity of 48 ft/s. Its height h in feet after t seconds is given by the function h= -16t2 + 48t + 6. In how many seconds does the ball reach its maximum height? Round to the nearest hundredth if necessary. What is the ball’s maximum height?

A. 1.5 s; 42 ft

B. 1.5 s; 114 ft

C. 3 s; 6 ft

D. 1.5 s; 54 ft

Answer 1

A. 1.5 s; 42 ft

Explanation:

1.5 sec and will reach a height of 42 feet

that is the vertex

for y=ax^2+bx+c

the x value of teh vertex is

the y value is found by subsituting the x value of the vertex for x

so

h=-16t^2+48t+6

a=-16

b=48

c=6

x value of vertex is

subsituting it for x we get

it reaches the max height of 42ft at 1.5 seconds