What is the minimum radius for safe circular flight?

[DJB1991]

Homework Statement

An airplane is flying in a horizontal circle at a speed of 141 m/s. The 94.2 kg pilot does not want his radial acceleration to exceed 8.88g

What is the minimum radius of the circular path?

Homework Equations

v^2/r

The Attempt at a Solution

141^2/.00888 kg

 

[jyothsna pb]

try using v^2/r<=8.88g

 

[jyothsna pb]

i don't think u have to take gravity cause its perpendicular to radial acceleration and it really has no effect (its a horizontal circle)

 

[pat666]

yeah i realized that as soon as i wrote it. i was thinking centripetal acceleration and vertical circle, don't know where i got that from

 

[pat666]

i don't know why they gave the pilots mass, it won't affect radial acceleration will it?

 

[pat666]

with your attempt why do you have 0.00888kg? a_C =v^2/r r=141^2/9.81*8.888? = 228

 

[Jokerhelper]

i don't know why they gave the pilots mass, it won't affect radial acceleration will it?

how does a helicopter lift-off?

 

[pat666]

evidently it will but are the pilot and the plane one entity? or are they considered as two separate masses. sorry I am asking more questions than djb991 i just covered this topic and don't understand it too well.

 

[Jokerhelper]

evidently it will but are the pilot and the plane one entity? or are they considered as two separate masses. sorry I am asking more questions than djb991 i just covered this topic and don't understand it too well.

sorry, completely misread about half of that problem. then yes, the mass of the pilot seems pretty insignificant considering the mass of the airplane.

 

[pat666]

with your attempt why do you have 0.00888kg? a_C =v^2/r r=141^2/9.81*8.888? = 228

is there anything you can see wrong with what I've done here? except the a_c should be a_r and there should be brackets around the bottom half.

 

[jyothsna pb]

pilot n airplane r considered as one entity
pilots mass or even the whole system mass won't affect its radial acceleration as its moving in a horizontal circle
141*141/r=8.88*9.8

 

[pat666]

yep that's exactly what I thought and said