physics
posted by Courtney .
A train travels at a constant speed around a curve of radius 225 m. A ceiling lamp at the end of a light cord swings out to an angle of 20.0º throughout the turn.
Draw a free body diagram?
What is the speed of the train?

Let the cord tension be T
T*cos20 = M*g
T*sin20 = M*V^2/R
Divide one equation by the other to eliminate T.
tan20*g*R = V^2
Solve for V
V = 28.3 m/s