How Does Friction Affect Energy Between Points B and C?

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Friction plays a crucial role in the energy transfer between points B and C, affecting both kinetic and potential energy. The man runs from point A to B at 40 m/s and then slows to 23 m/s at point C, covering a distance of 30 meters. The work done by friction can be calculated using the change in kinetic energy, which decreases as the man moves from B to C. The potential energy change from B to C also contributes to the energy loss, indicating that friction is responsible for the difference in energy states. Understanding these energy dynamics is essential for solving the problem accurately.
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A man who was first standing runs from the point A.His speed is 40 m/s in B and 23 m/s in C,where the distance BC=30 meters..a) What work does the force of friction over the man ( m=60kg)? b) Find the max height reached by the man in the C level.. image here http://i.imgur.com/HVd7UH2.jpg


I don't know how to find the quotient of the force of friction in the image? Because Work = -(quotient)* m*g*x.. I can find x because mv0^2/2+ +mv^2/2=mgh and I can find h,how about the quotient? does the angle help me?

how about point b? please help me..
 
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I don't know how to find the quotient of the force of friction in the image?
That is not asked.

What is the kinetic energy of the man in B and C? How does his potential energy change from B to C? You will see that the sum of both decreased - this difference is caused by friction.
 

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