A package is thrown down a curved ramp as shown in the figure. The package moves from A to B through a quarter-circle with radius R=3.00m. The mass of the package is 25.0kg. The package starts from rest at point A and there is no friction.
A) Find the speed of the package at the bottom of the ramp (point B).
B) Find the normal force that acts on the package at point B (Hint: Notice that here the Work-energy theorem may not be useful).
C) Consider now that the ramp is not frictionless and the speed of the package at the bottom is 6.00m/s. What work was done by the friction force acting on the package.