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llauren84
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Homework Statement
In an American football game, a 90.0-kg fullback running east with a speed of 5.00 m/s is tackled by a 95.0-kg opponent running north with a speed of 3.00 m/s. (a) Explain why the successful tackle constitutes a perfectly inelastic collision. (b) Calculate the velocity of the players immediately after the tackle. (c) Determine the mechanical energy that disappears as a result of the collision. Account for the missing energy.
Homework Equations
m1v1=m1+m2*v2
v2= m1/(m1+m2)*v1
The Attempt at a Solution
(a) Because they are stuck together, it is a perfectly inelastic collision.
(b)Theta= 40degrees = tan-1(3/5)
m1=90.0kg
m2=95.0kg
v1=(5.00i+3.00j)m/s= [tex]\sqrt{5.00^2+3.00^2}[/tex]m/s= 5.83m/s
v2= m1/(m1+m2)*v1
=(90kg/185kg)*5.83 m/s =2.84 m/s
v2x= 2.84*sin40degrees=1.82i
v2y= 2.84*cos40degrees=2.16j
So, the vector for the velocity after impact is (1.82i+2.16j)m/s
(c)w=[tex]\Delta[/tex]K=(1/2)m*[tex]\Delta[/tex]v2
w=(1/2)(m1+m2)(v22-v12)
w=-2.405kJ
This is the heat generated from the collision.
I really worked out the problem, but I don't know if it's correct. Please check it for me. Thanks.