Question

speed and velocity
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?
5 km/h
7 km/h
12 km/h
17 km/h

Explanation:

Step1: Determine the relative motion

Simon is moving away from Keesha at \(12\) km/h and throws the ball back at \(5\) km/h relative to himself.

Step2: Calculate the speed relative to Keesha

The speed of the ball relative to Keesha is \(12 - 5\) km/h.
$$12- 5=7$$

Answer:

7 km/h