# Math

posted by .

If a ball is shot projected straight upward at a rate of 64 feet per second from a rooftop, 80 feet above ground level, the height of feet above ground is modeled by the equation,
h(t)=-16t^2+64t+80
Find h(0), h(1),h(2)

Use the zero-factor property to determine how many seconds it will take for the ball to reach the ground? (What value of t makes h(t)=0)

• Math -

I will do one of them, you do the rest following my method, ok?

f(1) = -16(1)^2 + 64(1) + 80
= -16 + 64 + 80
= 128

when h = 0
-16t^2+64t+80 = 0
divide by -16
t^2 - 4t - 5 = 0
(t-5)(t+1) = 0
so t=5 or t=-1

clearly t > 0 ,so after 5 seconds it will reach the ground.

• Math -

Thank you so much. You really helped me understand. I can definitely finish the rest.

## Similar Questions

1. ### college algebra

Isn't this a plug and chug? I will be happy to critique your thinking. Your equal signs in the function are not correct, I assume that is a typo. suppose a baseball is shot up from thr ground straight up with an initial velosity of
2. ### Math

If a shot is fired directly upward at 1200 feet per second from a ground elevation of 8oo feet above sea level, how high would it go above the ground level?
3. ### Math-

A ball is thrown vertically upward with an initial velocity of 96 feet per second. The distance s (in feet) of the ball from the ground after t seconds is s(t)=96t-16t^2 a.) at what time will the ball strike the ground b.) for what …
4. ### Pre-Calculus

A ball is thrown vertically upward with an initial velocity of 64 feet per second. The distance(in feet) of the ball from the ground after t seconds is s=64t-16t. At what time will the ball strike the ground?
5. ### Math

A ball is tossed straight upward with an initial velocity of 80 ft per second from a rooftop that is 12 feet above ground level . The height of the ball in feet at time t seconds is given by h(t)= -16t^2 +80t+12 find maximum height …
6. ### math

An object that is falling or vertically projected into the air has it height, in feet, above the ground given by the formula below, where s is the height in feet, Vo is the original velocity of the object, in feet per second, t is …
7. ### Algebra 2

A shot put champion releases the shot from 6ft above the ground. The path of the shot is modeled by: h(d)=-0.02d^2+1.11d+c. How far does the shot travel before it hits the ground?
8. ### math

A robotic basketball player tosses a ball upward from a height of 7 feet, at an initial speed of 111 feet per second. The height of the ball is modeled by the equation: h=−16t2+111t+7, where h is the height above the ground in …
9. ### Precalculos

A ball is thrown vertically upward with an initial velocity of 96 feet per second. The distance s (in feet) of the ball from the ground after t seconds is S(t)=96t-16t^2. At what time t will the ball strike the ground?
10. ### Pre-Algebra

A ball is thrown straight up at 46 feet per second from about 6 feet above the ground. How long will it take for the ball to reach a height of 39 feet?

More Similar Questions