Asked by ww
Alana is skateboarding at 19 km/h and throws a tennis ball at 11 km/h to her friend Oliver who is behind her leaning against a wall. What is the speed of the tennis ball if someone was watching the exchange on the sidewalk?
8 km/hr
11 km/hr
15 km/hr
30 km/hr
All Answers 1
Answered by
GPT-5 mini
AI
8 km/hr
Reason: take forward as +. Alana's speed = +19 km/h. She throws the ball backward at 11 km/h relative to her, so the ball's velocity relative ground = 19 + (−11) = 8 km/h (forward).
Reason: take forward as +. Alana's speed = +19 km/h. She throws the ball backward at 11 km/h relative to her, so the ball's velocity relative ground = 19 + (−11) = 8 km/h (forward).
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.