Question

The prop. blade of an airplane is 2.80ft, and rotates @ 2200 r/min. What is the linear velocity of a point on the tip of the blade?

Answer 1

https://www.khanacademy.org/science/physics/torque-angular-momentum/torque-tutorial/v/relationship-between-angular-velocity-and-speed

Answer 2

Use

\[v=\omega(r)=\theta/t(r)\]


\[\theta = 2\pi rad\]
t= 1 rev
r = .5(2.8)

Answer 3

so them telling me the length of the blade holds no grounds?

Answer 4

Will have to look up how to calculate linear velocity.

Answer 5

all I could find was angular velocity , and after about 2 hours on a simple problem hat

Answer 6

isnt linear velocity the speed of the circumference?

Answer 7

speed over time

Answer 8

I know there's a relationship between the two.

Answer 9

I found this:
The formula for finding linear velocity is v = x / t. The x variable is distance traveled, and t is the time it took to travel the distance x. The v variable is the linear velocity.

radius = 1.4 feet
If prop rotates at 2,200 rev/min that equals 36.666 rev for every second
Each turn of the prop means that the tip has traveled 1.4 *2*PI = 8.7964594301 feet
Multiplying this by 36.666 rev per second equals
322.54 feet per second.

Answer 10

The distance from the prop center to the tip is half of 2.8 or 1.4
for each turn of the prop the tip must travel 1.4*2*PI feet.

Answer 11

so we take 2.80 and multiply in 1/2, that gives us half the blade length which is 1.4 ft. is that 1.4x2xpie?

Answer 12

which equals 8.7964594301 feet

Answer 13

now is that ft per second?

Answer 14

eventually it is feet per second. At this point we are only determining the distance traveled - which is 8.796 feet

Answer 15

persistence pays off i found my page

Answer 16

I'd like to thank ehuman and wolf1728, I couldn't have done it without you!

Answer 17

wait what am I talking about, im not done here.

Answer 18

(2200revs/min)(2 pi rad/rev)(1.4ft)=?

that is the equation you need

Answer 19

compare it to what i gave you before