surface area of two end: PI(4-2)* two ends
surface are of outer : PI*2*3
surface area of inner: PI*1*3
Total area: PI (3+6+2)
check my thinking.
Another question, hehe: By "two ends", you mean the radii of the circles?
The way I looked at was this :
Surface area of outside cylinder = 2pi(2) = 4pi .... 2pi(r)(h)
Surface area of inside of cylinder = 2pi(1) = 2pi
Surface area of top ("washer" shape) = pi(2^2) - pi(1^2) = 3pi
Now the question becomes whether to include the base in the surface area calculation.
Students in the last few days have been using the definition lateral surface area to exclude the base.
So if we include the base the total surface area would be 4pi + 2pi + 6pi = 12pi
if we exclude it then 9pi
Reiny is right on the ends, 3PI for each. I included the base.
Find the surface area of the resulting SOLID.
R = 2, r = 1, h = 3
Outer cylinder = 2R(Pi)h
Outer cylinder = 2(2)Pi(3) = 12Pi
Inner cylinder = 2r(Pi)h
Inner cylinder = 2(1)Pi(3) = 6Pi
Ends = [PiR^2 - Pi(1^2)]2
Ends = [Pi(2^2)-Pi(1^2)]2 = 6Pi
Total surface area = 24Pi
WHERE DID I GO WRONG, IF I DID??
Lateral surface area of cylinder standing on one end = 2(2)Pi(3) = 12Pi
Answer this Question
physics - A curcial part of a piece of machinery starts as a flat uniform ...
geometry - Find the surface area of each of the following a cube that is 4 cm by...
AP CALCULUS PLEASE HELP DUE TOMORROW! - 5. What are the dimensions of the ...
INTRO TO PHYSICS - Each of the following objects has a radius of 0.174 m and a ...
maths --plse help me.. - A toy is in the shape of a right circular cylinder with...
maths --Surface area and all that.. - A toy is in the shape of a right circular ...
physics - "A solid cylinder and a thin-walled hollow cylinder have the same mass...
physics - "A solid cylinder and a thin-walled hollow cylinder have the same ...
physics - A hypodermic needle consists of a plunger of circular cross-section ...
calculus help - A drinking cup is made in the shape of a right circular cylinder...