Question

Felipe is riding his skateboard toward Lilah at 15 km/h. He throws a football to Lilah. The football is thrown at 8 km/h. How fast is the football traveling when it reaches Lilah?

Answer 1

23 km/h

Step-by-step explanation:

Answer 2

Felipe is moving towards Lilah at velocity

`v_f = +15 km/h`
and the velocity of the football with respect to Felipe is

`v_b=+8 km/h`
Therefore, the velocity of the football relative to Lilah is the sum of the two velocities:

`v=v_f+v_b=15 km/h+8km/h = 23 km/h`