Attaching two questions, check out the picture please!

Question

mazehaq · Answer

attachment

mazehaq · Answer

I want to know if I did the first one correctly as well.

anonymous · Answer

yep they look good:)

mazehaq · Answer

I keep getting a weird answer for #2, it's a two part question & it's throwing me off a bit.

hartnn · Answer

you are $\huge \color{red}{\checkmark}$

parthkohli · Answer

1) One third of circumference.$$= {1 \over 3}{2\pi r} = {2 \over 3}\pi\cdot 9 = 6\pi \checkmark$$

mazehaq · Answer

How would I do #2?

parthkohli · Answer

OK, so you got with you $480\rm rev/min$... just convert 1 rev to the distance you cover in 1 rev which is your circumference.$$\rm \pi d = 26\pi$$So that's your circumference... but you move $C \times 480$ in a minute.

parthkohli · Answer

$12,480\pi$ is the distance in inches that you move.

parthkohli · Answer

Can you convert $\rm 12,480\pi$ to miles before proceeding?

mazehaq · Answer

Hold on, I am trying to write everything down

parthkohli · Answer

Well, it's almost 1 kilometer rounding to the nearest hundredth.

mazehaq · Answer

I need express my answer in miles.

parthkohli · Answer

So it's 0.6188 miles every minute.

parthkohli · Answer

Multiply that by 60.

mazehaq · Answer

I got 37.6 miles o_o but I didn't use the numbers you gave me