Answer:
39 maybe i don't know
Step-by-step explanation:
Answer:
$23.31
Step-by-step explanation:
$21 x 1.11 = $23.31
y-axis = altitude in feet
x-axis = minutes
slope = y/x = feet/minute
According to above data, we know that 1800 feet is y-intercept and slope is -300 feet per minute (why slope is negative? because its approaching ground at a constant speed)
a. slope = -300
y-intercept = 1800
b. y = -300 x + 1800
c. Here we are given x = 2 minutes
y = -300(2) + 1800
y = -600 + 1800
y = 1200
The balloon will be 1200 feet high above the ground in 2 minutes.
d. Here we are given 300 feet which is y, and find x minutes.
y = -300 x + 1800
300 = -300x + 1800
300 - 1800 = - 300x
-1500 = -300x
1500 = 300 x
x = 1500 / 300
x = 5
The balloon will reach 300 feet above the ground in 5 minutes.
e. It asking when the balloon will reach the ground, if the balloon reaches the ground than the height will be 0, therefore x-intercept (y=0).
y = -300 x + 1800
0 = -300 x + 1800
-1800 = -300x
1800 / 300 = x
x = 6
The balloon will reach the ground in 6 minutes.
<em>//Hope this helps</em>
Answer:
A: 779 cm²
B: 1837 cm²
Step-by-step explanation:
For both problems, use the formula for surface area of a cylinder:
SA = 2πr² + 2πrh
2πr² is the two bases.
2πrh is the curved surface.
<u>PROBLEM A</u>
"the cylinder is 60 cm long" is h = 60.
If given diameter, you can find "r" by dividing it by 2. d = 2r
Given d = 4, then r = 2.
SA = 2πr² + 2πrh
SA = 2π2² + 2π2(60)
SA = 8π + 240π Add
SA = 248π Exact answer
SA ≈ 779.114978 Answer on calculator
SA ≈ 779 Rounded answer
Remember to include the units.
The surface area is about 779 cm².
<u>PROBLEM B</u>
"80 cm long" h = 80.
"circumference of 22 cm". C = 22. Remember C = 2πr. Find "r".
C = 2πr
22 = 2πr
11 = πr
r ≈ 11/π
SA = 2πr² + 2πrh
SA = 2π(11/π)² + 22(80) Substitute 2πr with the circumference.
SA ≈ 1837.030992 Answer on calculator
SA ≈ 1837 Rounded answer
Remember to include the units.
The surface area is about 1837 cm².
