Answer:
10,500
Step-by-step explanation:
You must divide 52,500 by 5.
5 goes into the 5 in 52,500 one time. 5-5 is 0. 5 doesn't go into 2 so put a 0. 5 goes into 25 five times. 25-25 is 0. 5 goes into 5 one time. subtract and add the zeros at end. And you get 10,500
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:
The submarine would be 900 below the ocean surface after 12 minutes assuming it started its descent at the surface of the ocean.
Step-by-step explanation:
The formula for distance traveled (in this case the distance a submarine descends) over a period of time is:
d
=
r
⋅
t
where
d
is the distance traveled (or descended),
r
is the rate of travel and
t
is the time.
In this problem we are told the rate,
r
is 75 feet per minute. And, we are told the time,
t
, to calculate for which is 12 minutes.