# Circular Motion Ferris Wheel

I'm on the right track, but I'm stuck here....

The radius of a Ferris wheel is 5 m and it makes one rev in 10 sec

a Find the difference b/w the apparent weight of a passenger at the highest and lowest points, expressed as a fraction of his weight, W

b What would the time for one rev be if teh apparent weight at the top were zero?
c What would be the apparent weight at the low point??

I have at the top that

mv^2/r = mg - Fn

and at the bottom

mv^2/r = Fn -mg

I really dont undestand what a is asking...(Fnbottom - Fntop)/ W ??

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OlderDan
Homework Helper
Mehta29 said:
I really dont undestand what a is asking...(Fnbottom - Fntop)/ W ??
Yes you do. It's exactly what you said. Write your answer as Fnb - Fnt = _______W

but im confused as if anything else would be needed...liek that blank befor e the W...would i need to expand any further or would i just keep it
Fnbottom - Fntop = xW

b would just be v^2/r = g? and then t = 2pir/v

and c would be Fnb = mv^2/r + mg...but how would i eliminate m?

Last edited:
OlderDan
Homework Helper
Mehta29 said:
but im confused as if anything else would be needed...liek that blank befor e the W...would i need to expand any further or would i just keep it
Fnbottom - Fntop = xW

b would just be v^2/r = g? and then t = 2pir/v

and c would be Fnb = mv^2/r + mg...but how would i eliminate m?
Solve your earlier top and bottom equations for Fn. Take the difference between the two. Your result will be of the form
Fnb - Fnt = mA where A is a number that can be computed from the given information. You can do that. Once you have that form, multiply and divide by g
mA = mgA/g = WA/g
Fnb - Fnt = (A/g)W with A/g replaced by a number.

i got A and B...but how would i manage part c?

im not seein anyway to cancel out the mass...

OlderDan