Answer:
a) 2,350,000,000
b) 25,000,000
c) B
Step-by-step explanation:
a) 2350 X 1,000,000 = 2,350,000,000
b) 25 X 10^6 = 25,000,000
c) sqrt(90000) =300
Hello!
10 seconds to return to the ground.
7 seconds to reach 576 feet above the ground.
Find the amount of time taken to reach the ground by setting the equation equal to 0:
0 = -16t² + 80t + 800
Factor out -16 from the equation:
0 = -16(t² - 5t - 50)
Factor the terms inside of the parenthesis:
0 = -16(t - 10)(t + 5)
Find the zeros:
t - 10 = 0
t = 10
t + 5 = 0
t = -5
Time can only be positive in this instance, so the correct answer is 10 sec.
Find the time by substituting in 576 for the height:
576 = -16t² + 80t + 800
Subtract 800 from both sides:
-224 = -16t² + 80t
Rearrange:
0 = -16t² + 80t + 224
Simplify:
0 = -16(t² - 5t - 14)
0 = -16(t - 7)(t + 2)
t = 7 seconds.
