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Slam
Homework Statement
There is a subway derailed. Radius of an unbanked curve is 150 m. An unused strap hangs at a 15 degrees angle to the vertical just before the accident. Did the train exceed 35 km/h and what speed was it at just before the accident.
Homework Equations
F=ma=m(v^2/r)
The Attempt at a Solution
The angle of the Normal force is 75 degrees counterclockwise to the horizontal axis. The x-component of Force is m(v^2/r)=Ncos75
The y-component of Force is 0=Nsin75-mg
m=(Nsin75)/g Substitute this in for m in the x-component
((Nsin75)/g)(v^2/r)=Ncos75
v^2=g*r*tan75
g=35.28 km/h
r=.150 km
v=4.44 km/h