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ArbitrLikvidat [17]
3 years ago
14

Simon is riding a bike at 12 km/h away from his friend Keesha. He throws a ball at 5 km/h back to Keesha, who is standing still

on a sidewalk. How fast would Keesha say the ball is traveling?
Physics
1 answer:
pychu [463]3 years ago
3 0
So there are different ways this could be solved. I'll do try to explain it the way I was taught... 

Simon is riding his bike at 12 km/hr relative to the sidewalk, away from where Keesha is.

Simon throws the ball at Keesha, at 5 km/hr. 

Keesha sees the ball approaching her at (12-5) = 7 km/hr relative to the ground to her. 

Therefore the answer is: 7 km/hr


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Answer:

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Explanation:

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         T_{1y} = T₁ sin 60

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         T_{2y} = T₂ sin θ

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           T₂ cos θ = 50              (1)

to solve the system we divide the two equations

           tan θ = 113.4 / 50

           θ = tan⁻¹ 2,268

           θ = 66.2º

we caption in equation 1

           T₂ cos 66.2 = 50

           T₂ = 50 / cos 66.2

           T₂ = 123.9 N

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