Answer:
60
Step-by-step explanation:
220*2 = 440
+ 220/2 = 550
The equation gives the height of the ball. That is, h is the height of the ball. t is the time. Since we are looking for the time at which the height is 8 (h=8), we need to set the equation equal to 8 and solve for t. We do this as follows:




This is a quadratic equation and as it is set equal to 0 we can solve it using the quadratic formula. That formula is:

You might recall seeing this as "x=..." but since our equation is in terms of t we use "t-=..."
In order to use the formula we need to identify a, b and c.
a = the coefficient (number in front of)

= 16.
b = the coefficient of t = -60
c = the constant (the number that is by itself) = 7
Substituting these into the quadratic formula gives us:



As we have "plus minus" (this is usually written in symbols with a plus sign over a minus sign) we split the equation in two and obtain:

and

So the height is 8 feet at t = 3.63 and t=.12
It should make sense that there are two times. The ball goes up, reaches it's highest height and then comes back down. As such the height will be 8 at some point on the way up and also at some point on the way down.
Answer:
08-Oct-2009 — If a spherical balloon has a volume of 972 pi cubic centimeters, what is ... is 4.pi.r^2 (its area remember not volume) as 4/3.pi.r^3=972pi r=9 ... and it is good to know the squares of the next 10 numbers.
Answer:
D) 672 in³
Step-by-step explanation:
The volume of a rectangular prism is found by the <em>product of its length, width, and height</em>, so the equation is<em> V = l * w * h</em>.
Plug in: <em>V = 12 * 7 * 8</em>
Multiply: V = 672 in³