Projectile Motion: Frisbee Sliding up a Sloped Roof

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A student is analyzing the motion of a Frisbee thrown onto a sloped roof at a 30° angle, where it slides up the incline without bouncing. The Frisbee strikes the roof at 15.0 m/s and slides 10.0 m before entering free-fall, with a coefficient of kinetic friction of 0.460. The challenge lies in determining the maximum height reached after the Frisbee slides up, as the problem lacks mass information, complicating the use of force equations. A free-body diagram has been created, but the student is unsure how to calculate acceleration and the normal force without mass. The discussion emphasizes that the problem is solvable by applying Newton's second law to the object on the incline.
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Homework Statement


One side of the roof of a building slopes up at 30.0°. A student throws a Frisbee onto the roof. It strikes with a speed of 15.0 m/s and does not bounce, but slides straight up the incline. The coefficient of kinetic friction between the plastic and the roof is 0.460. The Frisbee slides 10.0 m up the roof to its peak, where it goes into free-fall, following a parabolic trajectory with negligible air resistance.

Homework Equations


Determine the maximum height the Frisbee reaches above the point where it struck the roof.

The Attempt at a Solution


honestly... i haven't been able to do much, I try to find the acceleration using F=ma, and then maybe finding the speed when it's at the top, and continue from there; but the problem doesn't have a mass, so i don't have a clue where to start in any type of formula except for the basic kinematic equations, but I'm not even sure how those can be applied.

I've created a free-body diagram of it, but as I said without any mass, and maybe even with it I don't know where to start ( this problem is unlike any other one we've had this chapter.) I assume that when it reaches 10m, it will have Vxf, and then I can use that as Vx0 for a new diagram for parabolic motion... but I don't know how to find A, since the only formulas for A involving force is Fk=Uk/N, and you can't get the normal force without M, because N = mass*Gravity, or since it's on a slant, n=mass*cos(30)
 
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Welcome to PF!

You are definitely on the right track. It's a 2 part problem where the answer the first part is the initial condition to the 2nd part. Just write the F = ma for the object sliding up the incline. You'll see that it is solveable.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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