Answer:
i) pi×4500 cm³
ii) pi×600 cm²
iii) 14 liters
Step-by-step explanation:
in general : the diameter is 30 cm, the radius is half of that (15 cm)
i)
the volume of a cylinder is base area times height.
Vc = pi×r²×h = pi×15²×20 = pi×225×20 = pi×4500 cm³
ii)
similar to volume, the side "mantle" area of the cylinder is the circumference of the base area times height.
surface area of the cylinder mantle is
Scm = 2×pi×r×h = 2×pi×15×20 = pi×30×20 = pi×600 cm²
iii)
for this we need now to do the multiplication with pi and then convert the cm³ to liters.
1 liter = a cube of 10 cm side length = 10×10×10 = 1000 cm³
pi×4500 = 14137.17 cm³ = 14.13717 liters or rounded 14 liters
Answer:
The fifth line contains the error.
Step-by-step explanation:
Line 1 is the equation.
Lines 2, 3, and 4 are correct.
The error is in the 5th line.
The square root of a negative number is not a real number, so if this problem is solved only with real numbers, there is no solution.
If imaginary numbers are allowed, then the last line should read:
5x+(-4)-5x=6x+4-5x
-4=x+4
x=-8
To get rid of 5x on the left side.
1/3 of 39,900 equals 1/3*39900
(1/3)*(39900/1)= 39900/3
39900/3= 13300
Final answer: 13,300
