Answer:
1.5 seconds
Step-by-step explanation:
h=-16t² – 16t+ 60
When the rock enter the water, the height is 0. ... h=0
0 = -16t² – 16t+ 60 = -4 * (4t² - 4t +15) = -4* (2t - 3) (2t +5)
2t-3=0 or 2t+5 = 0
t = 3/2 or t = -5/2 (time can't be negative)
t = 3/2 or 1.5
Answer:
i thank it is 25 seconds.
Step-by-step explanation:
We can create two points.
30 feet below the surface of the water 10 seconds after he entered the water
100 feet below the surface after 40 seconds
So we have (10, 30) and (40, 100)
Plug this values into the slope formula:
m = y2-y1/x2-x1
m = (100 - 30)/(40 - 10)
m = 70/30
m = 2 1/3
12 feet is the answer. 4 times 3 is 12.
Answer:
-5
Step-by-step explanation:
an easy way to do it is to flip it so its 7-12 or you can do 12-7 and you get 5 then just add a - sign but thats my way and its weird lol