Master Centripetal Force with These Final Questions | Fan & Airplane Examples

[wakejosh]

first off, thanks for all the help. My physics book got taken when my car got broken into and my backpack was taken. I have an old book and my pages don't coencide with my homework. everyone has been a big help. with that,, i just have two final questions about centripetal force:

1. A ventilation fan has blades 0.25 m long rotating at 2 rad/s.
What is the centripetal
acceleration of a point on the outer tip of a blade?


2. An airplane is a wide sweeping "outside" loop can create zero "g"
(weightlessness) inside
the aircraft cabin. What must be the radius of curvature of the
flight path for an aircraft
moving at 70 m/s to create a condition of "weightlessness" inside
the aircraft?


Im really not sure where to start with these, although I do realize that I need to account for gravity, just not sure what kind of equation I am looking for.

 

[BishopUser]

$$A_{centripetal} = \frac {v^2} {r}$$ don't put angular velocity into that either. That should get you started atleast

 

[wakejosh]

$$A_{centripetal} = \frac {v^2} {r}$$ don't put angular velocity into that either. That should get you started atleast

is the v^2 the velocity squared meaning the rad/s, or do i need to convert that to something else?

 

[BishopUser]

rad/s is an angular velocity, you need to somehow convert that into m/s

 

[wakejosh]

ok, so for 1 do i do this:

.25m * 2 rad/s = .5

.5^2 / .25 = 1 m/s/s

is this correct for 1?

 

[wakejosh]

and for 2:

9.8 = 70^2 / r

r = 500 m

are these correct?