Answer:
C. 9
Step-by-step explanation:
y = -4x^2 + 2kx
subtitute 3:
y = -4(9)^2 + 2k(9)
y = -4(81) + 18k
let y = 0
=> 0 = -324 + 18k
=> k = 324/18 = 9
this is my calculations hope it helps
There's more than one way to do this problem.
Try this: Mult. both 109 and 5 by 2, obtaining 218 and 10.
What is 218 div. by 10? Do this in your head.
The formula is K = v^2 /2
You are told K = 32.
Replace K and solve for v:
32 = v^2 / 2
Multiply each side by 2:
64 = v^2
Take the square root of both sides:
v = √64
v = 8 meters per second.