Alright so I'm doing this assignment and it is asking (Simon is riding a bike at 12km/h away from his friend Keesha, who is still standing on a sidewalk. How fast would Keesha say the ball is traveling? 5km/h
7km/h
12km/h
17km/h

I would've put 17km/h if it was that simon was moving towards Keesha but it says he's moving away so it would only make sense to subtract 12 from 5 but then that also makes no sense so now I'm just confused.

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Arocket starts from rest and moves upward from the surface of the earth. for the first 10.0 s of its motion, the vertical acceleration of the rocket is given by ay = 12.80 m/s32t, where the +y-direction is upward. (a) what is the height of the rocket above the surface of the earth at t = 10.0 s? b) what is the speed of the rocket when it is 325 m above the surface of the earth?