Finding Apparent Weight with Uniform Circular Motion

AI Thread Summary
To find the apparent weight of a passenger on a ferris wheel, the centripetal acceleration must be considered. The wheel completes three revolutions in 50 seconds, resulting in an angular velocity of 0.37 rad/s and a centripetal acceleration of 1.92 m/s². The apparent weight at the top of the wheel is calculated using the formula M(g - ω²r), where M is the mass, g is the gravitational acceleration, and ω²r represents the centripetal force. The correct calculation yields an apparent weight of 469 N for a 60 kg passenger. Thus, the apparent weight decreases at the top of the ferris wheel due to the effect of centripetal acceleration.
CalebtheCoward
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Homework Statement



A ferris wheel with a radius of 14.0 m rotates at a constant rate, completing three revolutions in 50.0 s. What is the apparent weight of a 60.0 kg passenger when she is at the top of the wheel?
Given choices: 532 N, 452 N, 562 N, 625 N, 469 N

Homework Equations



T=2∏/ω, a=(ω^2)r, F=ma

The Attempt at a Solution



3 rev/ 50 s = 0.37 (rad/s)
a=1.92 (m/s^2)
F=(a+g)m=(1.92+9.81 (m/s^2))(60.0 kg)=703.8 N
 
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Your attempt is a bit incomplete. You are forgetting to include the force due to centripetal accelaration which is
2R
Find it and subtract it from the value u got in ur attempt
The force equation on the man is
m(g+a)-mω2r
 
Firstly we should be clear about definition of weight ,as per halliday "The weight W of a body is the magnitude of the net force required to prevent the body from falling freely, as measured by someone on the ground"..Now what you have found in your attempt is weight at the lowest point on the wheel.At the topmost point it should be M(g-ω^2r)..think it like a body in an elevator moving downwards at acceleration of magnitude ω^2r. Mathematically you can remember weight as M(⃗g-⃗a). so at lowermost position ⃗g-⃗a will come out to be 9.8+ω^2r and at top 9.8-ω^2r. For this particular question answer is 469 N.
 
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