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Calculate the final speed (in m/s) of a 106 kg rugby player who is initially running at 7.75 m/s but collides head-on with a padded goalpost and experiences a backward force of 1.85 ✕ 10⁴ N for 7.50 ✕ 10⁻²s.

User Donel
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1 Answer

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Answer:

Final velocity will be -5.33 m/sec

Step-by-step explanation:

We have given mass of the rugby player m = 106 kg

Initial speed = 7.75 m/sec

Backward force
F=1.85* 10^4N

Time is given as
t=7.5* 10^(-2)sec

Impulse is given by impulse = force × time

So impulse
=-1.85* 10^4* 7.5* 10^(-2)=-1387.5N-s ( as force is backward )

We know that impulse is given by change in momentum

So
m(v_f-v_i)=-1387.5


106* (v_f-7.75)=-1387.5


v_f=-5.33m/sec

User Ozzymado
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