# Torque with constant circular velocity

1. The problem statement, all variables and given/known data

a passenger with height 175cmis driving on a city bus. The center of mass is at h=110cm above the middle point of the shoe which are 30 cm long. The passenger is standing in the direction of the ride.
h=175cm
h*=110cm
shoe size = 30 cm

b)
the bus is driving in a circle which has the radius of 20m with a constant speed of 20 km/h.For what angle relative to the vertical axis should the passenger lean so that he/she would not tip over.

2. Relevant equations
Fc=m*v2/r
Fn=m*g*cosα
Fx=m*g*sinα

3. The attempt at a solution
So here is what I tried to do
fc=m*(20/3,6)2/20……………… I got Fc=1,543m
and here is something I don’t understand. Since the centripetal force is acting toward the center of the circle, why is it incorrect to just use the Fx component of m*g
I tried doing it like this
Fc=1,543m Fx=m*g*sinα……since the body is not moving Torque=0
1,543m=m*g*sinα
sinα=(1.543*m)/(m*g) the masses cancel out
sin=1.543/9.8
sinα=0,157
α=9.05°

which is incorrect. The right answer is 8.9° and the end equation should look like this
tanα=v2/(r*g)
Can someone please explain or help me get to this equation tanα=v2/(r*g) [/b]
Thank you for reading

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