Question

A radial saw has a blade with a 7-inch radius. Suppose that the blade spins at 1300 rpm. (radians per minute).

a.) find the angular speed of the blade in rad/min.
b.) find the linear speed of the saw teeth in ft/s (feet per second).
USE (3.1416 for pi)

Answer 1

ok no, it did not specify that rpm meant radians per second

Answer 2

in part "a" it says radians per minute so I didn't know if that corresponded to the question

Answer 3

I'll assume 1300 rpm = 1300 revolutions per minute,

Answer 4

then, for part a) :
angular speed = \(2 \pi f = 2\pi*1300 = 2600 \pi \) rad/min

Answer 5

for pat b) :

linear speed = \(r \omega \)

\(r\) = radius
\(\omega\) = angular speed

Answer 6

you will need to convert the units .. .

Answer 7

i have never seen these formulas before lol

Answer 8

u will see it more... if you're doing uniform-circular motion problems.... :)

Answer 9

okay is that all i will need to do? ima keep this question open in case something comes up

Answer 10

what does the long f mean, after 2 pi?

Answer 11

f = frequency = 1300 revolutions per minute

Answer 12

okay lol thanks

Answer 13

linear speed = \(\large r \omega = 7 \times 2600 \pi \) inches/ minute

Answer 14

convert it to feet/second

Answer 15

so 7/12 for inches to feet and...8168(2600pi) would be 490080 in seconds?

Answer 16

1/12 for inches
1/60 for seconds

Answer 17

careful, minute is in

Answer 18

careful, minute is in denomunator

Answer 19

\(\large \mathbb{7\times 2600 \pi \frac{inch}{min} }\)

Answer 20

\(\large \mathbb{7\times 2600 \pi \frac{12inch}{12min} }\)

Answer 21

\(\large \mathbb{7\times 2600 \pi \frac{feet}{12min} }\)

Answer 22

\(\large \mathbb{7\times 2600 \pi \frac{feet}{12\times 60 seconds} }\)

Answer 23

\(\large \mathbb{\frac{7\times 2600 \pi}{12\times 60} \frac{feet}{ seconds} }\)

Answer 24

simplify

Answer 25

okay thank you so much!!!

Answer 26

you should get 79.4 feet/second

Answer 27

u wlc :)
btw, u may use wolfram for calculator :
http://www.wolframalpha.com/input/?i=%287*+2600+%5Cpi%29%2F%2812%5Ctimes+60%29

Answer 28

wow that is an awesome website thanks for all the help!

Answer 29

yes it is.... np =)