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A 90 kg football player runs right at 8 m/s and hit a 70 kg referee standing on the field causing the referee to go right at 5 m/s.

If this is an elastic collision, what would be the football player's velocity after colliding with the referee?

1 Answer

7 votes

Answer:

4.11 m/s to the right

Step-by-step explanation:


m_(p) u_(p) +m_(r) u_(r) =m_(p) v_(p) +m_(r) v_(r) \\\\90 kg * 8(m)/(s) +70 kg * 0(m)/(s) =90 kg * v_(p) +70 kg * 5(m)/(s) \\\\720(kgm)/(s) =350(kgm)/(s) +90kg*v_(p) \\\\v_(p) * 90 kg = 370(kgm)/(s) \\\\v_(p) = 4.11 (m)/(s)

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