There are 2 similar cylindrical bottles. The height of the smaller cylindrical bottle is 4cm and the height of the larger cylindrical bottle is 12cm.
Calculate the ratio of the surface areas of the cylindrical bottles. (I don't think sufficient info are available for us to work out the solution. Answer's 2:1)
But before this, theres this question. the top of the larger bottle has a circumference of 42cm. Find circumference of the top of the smaller bottle. Answer''s 14 cm. I am posting this here in case this first question somehow relates back to the 2nd question, which is the one I'm posing to you guys now. thanks!
i think the answer is wrong..
diameter of larger bottle = 42 divide by 22/7(pi) = 147/11
=>radius of larger bottle = 147/22
surface area of larger bottle = area of curved surface + area of top and bottom = (42 x 12) + (147/22 x 147/22 x 22/7) x 2 = 784 7/11cm sq
diameter of smaller bottle = 14 divide by 22/7 = 49/11
=> radius of smaller bottle = 49/22
surface area of smaller bottle = area of curved surface + area of top and bottom =(14 x 4) + (49/22 x 49/22 x 22/7) x 2 = 87 2/11 cm sq
its a ratio of 9:1..
when you are answering questions on similar figures, you can assume everything is similar. However, take note when you are calculating area and volume.
when you have a 1cm by 1cm square, the area is 1*1=1cm2
but when you have a 2cm by 2cm square, the area is 2*2=2^2=4cm2
So when you are working on area (be it surface area), take the power of 2.
In this question, ratio of big surface area: small surface area=12^2:4^2=9:1
for length, just do what you always do for similar triangle.
height of large bottle/height of small bottle=circumference of large bottle/circumference of small bottle
12/4=42/x
x=14cm
lol.. i went to calculate.. wtf..
There are 2 similar cylindrical bottles. The height of the smaller cylindrical bottle is 4cm and the height of the larger cylindrical bottle is 12cm.
Calculate the ratio of the surface areas of the cylindrical bottles.
This alone can solve the question...
4^2 : 12^2
16:144
1:9