Angular velocity of a ferris wheel

AI Thread Summary
The discussion revolves around calculating the angular velocity of a ferris wheel where passengers experience zero gravity at the top. The passenger's weight is given as 367 N, and the radius of the wheel is 14 m. The calculations initially provided suggest an angular velocity of approximately 0.835 rad/s, but confusion arises regarding the use of weight versus mass in subsequent calculations. A correction is needed to properly account for the passenger's mass when determining the weight felt at the bottom of the wheel, leading to a recalculated force of approximately 230.43 N. The thread highlights the importance of distinguishing between weight and mass in physics problems.
kimikims
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This is a hard problem! :cry: Anyone know what my mistakes are??

-----
A passenger on the ferris wheel normally
weighs 367 N. The ferris wheel has a 14 m radius and is
equipped with a powerful motor. The operator revs it up so that the customers at the top of the wheel feel zero g's (they momentarily
lift slightly of their seats). The acceleration of gravity is 9.8 m/s^2

1) At what angular velocity will this occur?
Answer in units of 1=s.

N = 367 N
R = 14m
g = 9.8 m/s^2
N = 0

Fc = mg = m(V^2/R)
gR = V^2

(9.8)(14) = v^2 = 137.2 = 11.71

(Angular Velocity) W= V/R

11.71 / 14 = .835

2) Assume: The rotating angular velocity is
same as in Part 1.
What weight does the customer feel at the
bottom of the wheel? Answer in units of N.

Fc = N - mg = m(V^2/R)

N = mg + m(V^2/R)

V = WR

N = mg + m [(W^2 x R^2)/(R)]

= mg + mW^2R

= (367)(9.8) + (367) (.84)^2 (14)

= 7221.9728
 
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kimikims said:
1) At what angular velocity will this occur?
Answer in units of 1=s.

N = 367 N
R = 14m
g = 9.8 m/s^2
N = 0

Fc = mg = m(V^2/R)
gR = V^2

(9.8)(14) = v^2 = 137.2 = 11.71

(Angular Velocity) W= V/R

11.71 / 14 = .835
Looks OK to me. What are the units of your answer?
2) Assume: The rotating angular velocity is
same as in Part 1.
What weight does the customer feel at the
bottom of the wheel? Answer in units of N.

Fc = N - mg = m(V^2/R)

N = mg + m(V^2/R)

V = WR

N = mg + m [(W^2 x R^2)/(R)]

= mg + mW^2R

= (367)(9.8) + (367) (.84)^2 (14)

= 7221.9728
One problem: 367 N is the passenger's weight, not mass!
 
Another hint for part 2 is that the magnitude of the centrifugal force is always the same. If you understand that, you should be able to immediately write down the correct answer.
 
kimikims said:
This is a hard problem! :cry: Anyone know what my mistakes are??

-----
A passenger on the ferris wheel normally
weighs 367 N. The ferris wheel has a 14 m radius and is
equipped with a powerful motor. The operator revs it up so that the customers at the top of the wheel feel zero g's (they momentarily
lift slightly of their seats). The acceleration of gravity is 9.8 m/s^2

1) At what angular velocity will this occur?
Answer in units of 1=s.

N = 367 N
R = 14m
g = 9.8 m/s^2
N = 0

Fc = mg = m(V^2/R)
gR = V^2

(9.8)(14) = v^2 = 137.2 = 11.71

(Angular Velocity) W= V/R

11.71 / 14 = .835

2) Assume: The rotating angular velocity is
same as in Part 1.
What weight does the customer feel at the
bottom of the wheel? Answer in units of N.

Fc = N - mg = m(V^2/R)

N = mg + m(V^2/R)

V = WR

N = mg + m [(W^2 x R^2)/(R)]

= mg + mW^2R

= (367)(9.8) + (367) (.84)^2 (14)

= 7221.9728


So for part 2...

it should be uhm

(11.71) (9.8) + (11.71) (.84)^2 (14)

=230.43 N?
 
How did you get a mass of 11.71 kg? The passenger's normal weight is 367 Newtons...and

weight = mass * g.
 
kimikims said:
So for part 2...

it should be uhm

(11.71) (9.8) + (11.71) (.84)^2 (14)

=230.43 N?


So would it be...

(37.4) (9.8) + (37.4) (.84)^2 (14)

= 735.97 ?
 
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