Answer:
10 kph
Step-by-step explanation:
Find the speed of the current of the river.
20/(20 - c) + 180/(20 + c) = 8
20(20 + c) + 180(20 - c) = 8(400 - c^2)
8c^2 - 160c + 800 = 0
8(c^2 - 20c + 100) = 0
8(c - 10)^2 = 0
c = 10
The speed of the current of the river is 10 km/hour.
Answer:
the slope is -2/3x and the y intercept is 1
Step-by-step explanation:
When the football is 81 feet high, it will be √ 3 / 8 seconds
<h3>Function</h3>
Function relates input to output. Therefore,
Therefore,
t = number of seconds
h(t) = - 16t² + 75
h(t) = 81 ft
Therefore,
81 = - 16t² + 75
- 16t² = 81 - 75
- 16t² = 6
divide both sides by -16
t² = 6 / -16
t² = - 3 / 8
square root both sides
t = √ 3 / 8 seconds
learn more on function here: brainly.com/question/4418459
