- #1
bob1182006
- 492
- 1
Not original #'s but same questions:
A 750N child rides a ferris wheel that is moving at a constant velocity. At the highest point the child has an apparent weight of 650N.
(a) what is the acceleration of the wheel?
(b) what is the apparent weight of the child at the lowest point?
F=ma
a=v^2/R
Since the wheel is accelerating it's not an inertial frame so there's a pseudoforce (centrifugal?) acting on the child outward while the acceleration of the wheel is pointing inward to the center.
W=750N, W=mg, mg=750N, m=750N/g~76.4kg
(a).
at the top of the ferris wheel the child experiences the downward force of the acceleration and gravity. the centrifugal force (C) is upward:
C-mg=m(-a), C-mg=-ma
at the top -ma = apparent weight:
C-mg=650N, C=650N+mg=650N+750N=1400N
C/m-g=-a
g-C/m=a
9.81-(1400)/76.4kg=9.81-18.3=-8.49 m/s^2
(b).
at the bottom acceleration is up, gravity downward, as well as C.
-C-mg=ma
-1400N-750N=-2150N apparent weight, -gives direction down so the child thinks he weighs 2150N.
I'm not even sure if this problem has a numerical solution (no R, v given)
Homework Statement
A 750N child rides a ferris wheel that is moving at a constant velocity. At the highest point the child has an apparent weight of 650N.
(a) what is the acceleration of the wheel?
(b) what is the apparent weight of the child at the lowest point?
Homework Equations
F=ma
a=v^2/R
The Attempt at a Solution
Since the wheel is accelerating it's not an inertial frame so there's a pseudoforce (centrifugal?) acting on the child outward while the acceleration of the wheel is pointing inward to the center.
W=750N, W=mg, mg=750N, m=750N/g~76.4kg
(a).
at the top of the ferris wheel the child experiences the downward force of the acceleration and gravity. the centrifugal force (C) is upward:
C-mg=m(-a), C-mg=-ma
at the top -ma = apparent weight:
C-mg=650N, C=650N+mg=650N+750N=1400N
C/m-g=-a
g-C/m=a
9.81-(1400)/76.4kg=9.81-18.3=-8.49 m/s^2
(b).
at the bottom acceleration is up, gravity downward, as well as C.
-C-mg=ma
-1400N-750N=-2150N apparent weight, -gives direction down so the child thinks he weighs 2150N.
I'm not even sure if this problem has a numerical solution (no R, v given)