# Angular Motion on a Plane

1. Nov 15, 2005

### SS2006

The human body can safely stand an acceleration 9 times that due to gravity. With what minimum radius of curvature may a pilot sfely turn the plane upward at the end of a dive if the plane's speed is 770km/h.

i did a quesotin before this, which had a roller coaster
i did mgh at a = 1/2 mv square at a + mgh b. my v square was derived
froma free body diagram i drew, and i set mvsquare/r = fnet
and rearranged until i had the equation equal to V.
and then solved for H (from mgh at a) and i got the answer.
For this i dont know wat to do, can i use the same formula, but i dont have both heights, just the first one
i just wanted a startup

2. Nov 15, 2005

### Fermat

The problem has to do with centripetal acceleration.

Can you see how to set up eqns for centripetal acceln/force from the info given ?

3. Nov 15, 2005

### andrewchang

energy isnt necessary for this question. It's all centripetal motion.

4. Nov 15, 2005

### SS2006

reallyy! so this is different from the roller coaster q
im surprised now
what formulas may help

5. Nov 15, 2005

### SS2006

somebody........

6. Nov 15, 2005

### Fermat

What is the formula for the centripetal force on a body travelling in a circle,of radius R, with an angular velocity of ω ?

7. Nov 15, 2005

### SS2006

v = w square tiems r?

or
mv square over r

Last edited: Nov 15, 2005
8. Nov 15, 2005

### Fermat

Ok, this becomes,

Fc = mv²/r

and you want to find r.

What is the maximum value that Fc can be such that the pilot only experiences 9g ?

Then solve for r.

9. Nov 15, 2005

### SS2006

kkk i see
what bout mass
can i lave that 1?

10. Nov 15, 2005

### Fermat

The mass will cancel out.

11. Jul 3, 2006

### vijay123

ans.....518.69 meters
how disgracful of u guys. cant even solve such easy question.
haha....got outbeaten by a 14 year old nutcase

12. Jul 3, 2006

### Hootenanny

Staff Emeritus
It is much more productive, if one guides a poster through the question rather than providing answers or solutions. What has SS2006 gained from your post?

13. Jul 3, 2006

### Hawknc

One would hope only confirmation, because if he's still waiting on an answer then his assignment might be a bit late. ;)

14. Jul 3, 2006

### Hootenanny

Staff Emeritus
Didn't spot the date

15. Jul 3, 2006

### vijay123

lol...sry guys..i jus did dat for fun...
ok here it goes....
if you sub. in the values of the porblem by making r the subject of the formula, i got the ans.
were v is velcity, m is mass and g is 9.8ms(sqaured).
remeber to convert the km/h into m/sec.
sry for any hurt feelings
that wus jus for fun,
regards
vijay

16. Jul 3, 2006

### vijay123

lol, i glanced through the pages and found this, the prob. wus easy yet know one gave a definate ans to the solution. thats were i budged in......sry..guys.

17. Nov 22, 2011

### arminyazdan

how we should cancel m by this formule mv^2/r = ma ?