see the attached file this is the question of class 9 NCERT book physics question force and law of motion give me the answer fast otherwise wrong answer will be reported and maybe their account banned so Spammer keep away
Answers
Question :
A hockey ball of mass 200 g travelling at 10 m/s is struck by a hockey stick so as to return return it along its original path with the velocity of 5 m/s. Calculate the change of momentum occured in the motion of the hockey ball by the force applied by the hockey stick.
Answer :
a) Calculate the initial momentum
→ Mass of hockey ball (m₁) = 200 g = 0.2 kg
Initial velocity (v₁) = 10 m/s
→ Initial momentum = m₁ × v₁
→ Initial momentum = 0.2 × 10
→ Initial momentum = 2 kg m/s
b) Calculation of final momentum
→ Mass of hockey ball (m₂) = 200 g = 0.2 kg
→ Final velocity (v₂) = - 5 m/s (Reverse direction)
→ Final momentum = m₂ × v₂
→ Final momentum = 0.2 × (-5)
→ Final momentum = - 1 kg m/s
Now,
→ Change in momentum = Final momentum - Initial momentum
→ Change in momentum = - 1 - 2
→ Change in momentum = - 3 kg m/s
Thus,the change of momentum of the hockey ball is 3 kg m/s.
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