Question

Write an expression that could be use to change 5 revolution per minute to radian per second.

Answer 1

\[\frac{5rev}{1min}\frac{1min}{60sec}\frac{2pi\ rads}{1rev}\]

Answer 2

1min = 60sec

1min/60sec is an equivalent statement that means "1"; when we multiply by "1" the value never changes, only the way it looks

Answer 3

2pi rads = 1 revolutions;

2pi rads/1rev is a useful form of "1"

Answer 4

cancel "like terms" and simplify

Answer 5

than what answer?

Answer 6

"Write an expression that could be use to change"

that IS the answer; the just change 5 revs to N revs and 1min to Mmin and cancel out "like terms"

Answer 7

2pi rads = 1 revolutions
than 5 revolutions = 10 pi radi = 1800?

Answer 8

\[\frac{5\cancel{rev}}{1\cancel{min}}\frac{1\cancel{min}}{60sec}\frac{2pi\ rads}{1\cancel{rev}}\]
\[\frac{5(2pi)\ rads}{60\ sec}\]
\[\frac{(2pi)\ rads}{60\ sec}X\]

Answer 9

10pi rads in 1 minute then

10/60 = pi/6 rads per sec

Answer 10

6 radian=6(180)=1080?

Answer 11

pi radians = 180 degrees
\[\frac{pi\ radians}{180\ degrees}= 1\]
\[\frac{180\ degrees}{pi\ radians}= 1\]
\[\frac{6\ radians}{1}*\frac{180\ degrees}{pi\ radians}\]
\[\frac{6\ \cancel{radians}}{1}*\frac{180\ degrees}{pi\ \cancel{radians}}\]
\[\frac{6*180}{pi}\ degrees\]

Answer 12

you have to divide out the "pi" that is inherent in the radian measure; so it isnt just 1080; its 1080/pi

Answer 13

amistre please! come back I need help

Answer 14

you can always type up a new question for others to engage in as well :)

Answer 15

I don't get how you caculator from
5(2pi ) ra/60 second ?

Answer 16

its all about changing the way it looks; your redressing the problem, and not changing the value

Answer 17

we redress it by substituting in equivalent expressions ....

Answer 18

sorry I don't get how you come up 1080/pi

Answer 19

I'm slow

Answer 20

to change from radians to degrees; we have to divide out a pi; radians always include a pi, whether you see it or not.

Answer 21

6 radians has a "pi" built into it simply because it is a radian measure

Answer 22

5radi=1800?
2pi=360
1800(360)/60 =1080?

Answer 23

lets start by stating the problem; that way i can stay on track in my head :)

Write an expression that could be use to change 5 revolution per minute to radian per second.

Answer 24

5 turns around means 5(2pi)radians = 10pi radians, right?

Answer 25

yes

Answer 26

10pi radians every 1 minute right?

Answer 27

1 minute = 60 seconds; so 1min/60secs = 1; agree?

Answer 28

yes

Answer 29

(10pi rads every 1 minute) ; so if we divide this by 60 seconds we get:

10pi rads 1 minute 10pi rads
-------- every ------- = --------- every time, right?
60 sec 60 sec 60 sec

Answer 30

than 10pi/60 second?

Answer 31

reduce it down to 1 sec;

10pi rads 1pi rad
-------- = ------- = (pi/6 rads) every second
60 sec 6 sec

Answer 32

I don't get last part

Answer 33

do you agree that we can get it down to:

pi rads every 6 seconds

at least?

Answer 34

5(2pi rads) every 1 minute

10pi rads every 1 minute; 1 minute = 60 seconds

10pi rads every 60 seconds ; reduce

pi rads every 6 seconds .... you agree?

Answer 35

yes

Answer 36

good; but the question ask us for every 1 second; not every 6 seconds right?; so we have to reduce again by dividing at all by 6

5(2pi rads) every 1 minute

10pi rads every 1 minute; 1 minute = 60 seconds

10pi rads every 60 seconds ; reduce

pi rads every 6 seconds
--- ---
6 6

pi/6 rads every 1 second

Answer 37

answer=6?

Answer 38

\(\cfrac{pi}{6}\) rads every 1 second, would be the answer; not "6"

Answer 39

wait
=30

Answer 40

30?

Answer 41

..... what are you seeing that makes you think the answer is anything other than \(\cfrac{pi}{6}\) ?

Answer 42

pi=180?
180/6=30

Answer 43

pi does not equal 180; pi = 3.14159...

Answer 44

ahhh ..... then yes

Answer 45

pi/6 = 30 degrees :)

Answer 46

\[\frac{pi}{6}radians=\frac{180}{6}degrees=30degrees\]

Answer 47

I'm confuse
pi=180
pi=3.14
any way thank you fo be patient

Answer 48

recall when we did: 1 minute = 60 seconds? that is a relationship between minutes and seconds.

1m = 60s is true if we use the relationship between minutes and seconds;

the same thing holds for the relationship between radians and degrees; (pi)r = 180d only means something when we are using it in this context.

Answer 49

if we ignore the relationship and strip away the equivalency; it becomes nonesense:

1 = 60 is nonsense on its own

pi = 180 is nonsense on it own

Answer 50

ty, I get it now