What Formula Determines Average Velocity During Impact?

AI Thread Summary
To determine the average velocity during impact, the formula vave = (v1 + v0)/2 is suggested, assuming constant acceleration. The boy's weight is clarified as a force, equating to 700N when considering gravitational acceleration. The calculated impact velocity is 7.68 m/s, with an impulse of 536.7 kg*m/s. Understanding the distinction between weight and mass is emphasized, reinforcing the need for accurate unit application. The discussion focuses on the correct application of physics principles to find average velocity.
Atilla1982
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A boy with a weight of 70 kg jumps down from a 3 meter high tree. His velocity on impact I have found to be 7,68 m/s and the impulse is 536,7kg*m/s. Now I need to find the average velocity during impact. What formula do I have to use?
 
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What's the definition of average velocity?
 
I suppose, if acceleration is constant, then:

vave. = (v1 + v0)/2

An important point I'd like to raise here:

Weight is a force, therefore it has the units of Newtons. Obviously the man doesn't have a mass of 7kg so I can only assume the his weight is 700N (with g = 10ms-2).

Regards,
Sam
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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