A#22 (due 4/2)

Chapter 9 Closure Review (do all problems)

A#22 Handout (front)
A#22 Handout (back)

Refer to all of the previous lecture notes we have done in Unit 9 for further assistance on the material, specifically 9.1.4 - Ratio of Volumes if you didn't get a great grasp on that material yet.

Much of the work is also very similar to the work done in the classwork assignments CW#5 - Ratio of Similarity and CW#6 - Surface Area & Volume Practice.

EDIT:

Answer Key (front)
Answer Key (back)

I spent way to much of my time drawing the net on the figure.

Quinton R. wrote:

I spent way to much of my time drawing the net on the figure.

I'll be honest, this assignment took me about ten minutes to do. I'm not bragging about it or anything like that, but it's just an indicator that if something is taking too long on it, then we will need to talk about how to approach it the right way.

I'm not saying you in particular, though. I just mean in general. I'll scan my actual paper (with solutions) and put it up on the original post tomorrow.

I am just picky about my drawings and kept messing up other then that it did'nt take that long

Quinton R. wrote:

I am just picky about my drawings and kept messing up other then that it did'nt take that long

I figured as much. I thought you actually had a question on the net itself. If you still do, just remember it is a large 112 mm x 28 mm rectangle split into eight congruent 14 mm x 28 mm rectangles, with regular octagons on top and bottom (with side lengths of 14 mm, no less).

I don't get how to do #2 and how to just find the volume of just the salive of cake

Stephanie R. wrote:

I don't get how to do #2 and how to just find the volume of just the salive of cake

It's just like finding the area of the sector of a circle. First find the volume of the entire cake, then find out what fraction of the cake is cut out (assume the cake was an entire 360 degree cylinder). Set up a proportion to solve for that unknown value.

Reply again if that still doesn't make sense.

I found the area of the sector of a circle and the volume of the whole cake then what do I do

Stephanie R. wrote:

I found the area of the sector of a circle and the volume of the whole cake then what do I do

Oh, I said you do it like you do taking the area of the sector of a circle. Instead of a sector, this time it will be a slice (I don't know if there is an actual word for it... maybe they call it "volume of a sector" actually).

I'm guessing you got a volume of 294π in³ for the whole cake, correct (π = pi, by the way)? Well, a slice that is cut with a central angle of 38° means that you cut exactly 38/360th's of the cake.

You can set up a proportion, such as:

38/360 = x/294π

And solve for x.

This proportion says: "If I cut out a slice of cake that is this amount of the entire cake (38/360), the volume of my slice will be that same fractional amount of the volume of my entire cake (294π in³)."

Does that make any more sense? If it still doesn't, I'll scan and post my solution for it.

Yea makes sense thanks

Stephanie R. wrote:

Yea makes sense thanks

No problem! Feel free to PM me on what you get (or you can put it here if you want).

Just a strange quip, by the way... we leave answers in terms of pi sometimes because we want exact values. Well, this will be a case where 38/360 in itself is not an exact value, so when you get your answer, go ahead and multiply it by pi in your calculator, then round off from that.