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

Question

ArbitrLikvidat [17]

2 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] · Answer 1 · 2022-06-24T21:43:33+03:00

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