When at height>0, that is when it is below the water
find zeroes
0=-16x^2+18x
0=x(-16x+18)
solve
0=x
0=-16x+18
16x=18
x=18/16
x=9/8
from x=0 to x=9/8
9/8 seconds or1.125 seconds
2/4, the reason is because there is 2 sides to the coin, and its like each time you're flipping there is 1 chance for each side.
Answer:
A. 20
Step-by-step explanation:
We know that there are 8 eights in a whole, and a whole is equal to the number 1. The number 2 consists of two wholes, and so we multiply 8 by 2.
8 wholes in each 1 × 2 ones = 16 wholes
Now, we know that the number 2 is equal to 16 wholes, so now we need to find how much 1/2 of a whole is worth.
1 whole = 8 eights, so divided by 2, it would be 4 eights for a half of a whole.
So, we add 16 + 4 to get the result of 20.