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cdornz
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Homework Statement
A 120 pound person is sitting on a scale during a roller coaster ride. As the roller coaster goes over the top of a curve whose radius is 30 feet, the scale indicates a force of 25 pounds. The average speed of the roller coaster doesn't change while over this curve.
A) What forces are acting on the person?
B) Specify the magnitude and direction of each of the forces
C) Draw a free body diagram of the person
D) Describe the acceleration of the person
E) How fast was the roller coaster moving at that time?
Homework Equations
I know that a=mv(squared)/r : This equation goes into the right side of the ƩF=ma.
I know how to draw a free body diagram, start with the object at the center and draw the forces outward.
The Attempt at a Solution
A) I believed the forces to be: Fg=weight of person; Fn=force perpendicular to interface; Ff=mv(squared)/r
B) Fg=120pd, down; Fn=up, don't know magnitude; Ff=(120)v(squared) and I believe this is pointing inward, but I'm kind of confused by that.
C) This I am able to draw if I know the correct direction of the forces.
D) I have no idea how to get the acceleration, but I do have the equation. a=v(squared/r). Problem is, I only have the radius so I don't know how to go about solving for acceleration.
E) This also means I don't understand where to start to figure out the velocity of the roller coaster.