Answer:
a) t = 0.54 seconds
b) t = 8 seconds
Step-by-step explanation:
Given in the question the equation
h = 40t - 5t²
<em> where h is height in meters</em>
<em> t is time in seconds</em>
<em />
Time it took to reach 20 meters
20 = 40t - 5t²
-5t² + 40t - 20 = 0
by using quadratic formula for factorisation
<h3>t = (-b± √(b)² - 4(a)(c) ) / 2(a)</h3>
t = 0.54 (upward motion)
or
t = 7.46 (downward motion)
b) Time it took to reach the ground
at ground h = 0
So,
0 = 40t - 5t²
t(40 - 5t ) = 0
t = 0 (at starting point)
or
40 -5t = 0
5t = 40
t = 40 /5
t = 8 seconds
Answer:
3
Step-by-step explanation:
Hello from MrBillDoesMath!
Answer:
7.7 % (approximately)
Discussion:
65 * x% = 65 * (x/100) = 5 => (multiply both sides by 100)
65 *( x/100)* 100 = 5 * 100 =>
65x = 500 =>
x = 500/65 = 7.7 (approx)
Regards,
MrB
P.S. I'll be on vacation from Friday, Dec 22 to Jan 2, 2019. Have a Great New Year!
Answer:
Multiply the decimal by 100, then just add the percent symbol right after.