Throwing a frisbee and measuring change in mechanical energy

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SUMMARY

The discussion focuses on calculating the change in mechanical energy (Emec) of a thrown Frisbee due to air drag. The Frisbee, weighing 75g and thrown from a height of 1.1 m with an initial speed of 12 m/s, reaches a height of 0.1 m with a final speed of 10.5 m/s. The participants conclude that the reduction in Emec due to air drag is 0.53 J, despite initial calculations suggesting a change of -0.61 J. The need to separate velocity into x and y components for accurate calculations is debated but ultimately deemed unnecessary for this problem.

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sjcorona
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A 75g Frisbee I thrown from a point 1.1 m above the ground with a speed 12 m/s when it has reached a height $.1 m its speed is 10.5 m/s What is the reduction in Emec of the frisbee-earth system because of air drag?


At first I thought Since ΔEmec= Δk+Δu the change is -0.61 J
Then I reasoned that only the kinetic is affected by drag Δk= -1.3 J
Now I'm wondering if I need to split the velocity into x and y components so I can separate the decrease due to gravity and the decrease due to drag? But I don't thinknthats what they want me to do. According to the guide The answer ends up being 0.53 J
 
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Calculate the total mechanical energy at each point.
 
I did that too,Emec2 - Emec1 is still 0.61
 
I don't see how you got that answer (or the guide's answer). What is the final height of the frisbee? Is it 0.1 m?
 

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