# math

posted by lee

A ball is thrown into the air with an upward
velocity of 40 ft/s. Its height h in feet after t seconds
is given by the function h = -16h 2 + 40t + 6.

A. In how many seconds does the ball reach its
maximum height?
B. What is the ball's maximum height?

1. Bosnian

If your expression mean h = - 16 t² + 40 t + 6 then:

Vertex of this quadratic function have coordinates:

t = - b / 2a , h = c - b² / 4a

In this case:

a = - 16 , b = 40 , c = 6

So:

t = - b / 2a = - 40 / [ 2 ∙ ( - 16 ) ] = - 40 / - 32 = ( - 8 ) ∙ 5 / ( - 8 ) ∙ 4 = 5 / 4 = 1.25 sec

h = hmax = c - b² / 4a = 6 - 40² / [ 4 ∙ ( - 16 ) ] = 6 - 1600 / - 64 = 6 + 25 = 31 ft

2. Henry

A. V = Vo + g*t = 0,
40 + (-32)t = 0,
t = 1.25 s.

B . h = -16*1.25^2 + 40*1.25 + 6 = 31 Ft.

## Similar Questions

1. ### calculus

a ball is thrown directly upward with a velocity of 40 feet/seconds. its height in feet after t seconds is given by h(t)equals 40t-16t squared
2. ### calculus

a ball is thrown directly upward with a velocity of 40 feet/seconds. its height in feet after t seconds is given by h(t)equals 40t-16t squared
3. ### math

A ball is thrown into the air with an upward velocity of 20 ft/s. Its height (h) in feet after t seconds is given by the function h(t) = –16t^2 + 20t + 2. How long does it take the ball to reach its maximum height?
4. ### Algebra

A ball is thrown into the air with an initial upward velocity of 45 ft/s. Its height (h) in feet after t seconds is given by the function h = –16t² + 45t + 6. After about how many seconds will the ball hit the ground?
5. ### Algebra 1

A ball is thrown into the air with the in initial upward velocity of 45 ft/s. It's height (h) in feet after t seconds is given by the function h=- -16t^2+45t+6. After about how many seconds will the ball hit the ground?
6. ### Algebra 1

A ball is thrown into the air with the in initial upward velocity of 60 ft/s. It's height (h) in feet after t seconds is given by the function h=- -16t^2+60t+6. What will the height be at t=3 seconds?
7. ### calculus

velocity of a ball- if a ball is thrown into the air with a velocity of 40 ft/s, its height (in feet) after t seconds is given by y=40t-16t^2. find the velocity when t=2
8. ### Math

A ball is thrown into the air with an upward velocity of 48ft/s. It's height h in feet after t seconds is given by the function h=-16t^+48t+8. In how many seconds will the ball hit the ground?
9. ### Algebra

A ball is thrown into the air with an initial upward velocity of 60 ft/s. Its height (h) in feet after t seconds is given by the function h = –16t² + 60t + 6. What will the height be at t = 3 seconds?
10. ### algebra

A ball is thrown into the air with an upward velocity of 40 feet per second. Its height, h, in feet after t seconds is given by the function h(t)=-16t^2+40t+10. a. What is the ball’s maximum height?

More Similar Questions