I think it's B ,go to physicsclassroom.com Newton's second law
The answer is B.
She can measure the mass of the water, marble and the graduated cylinder with the balance.
The volume of the water can be shown on the marked graduated cylinder, the volume of the marble can be measured by the volume difference of the water before and after the marble is put in.
You said that she's losing 1.9 m/s of her speed every second.
So it'll take
(6 m/s) / (1.9 m/s²) = 3.158 seconds (rounded)
to lose all of her initial speed, and stop.
Answer:
I'd say C is the answer they want, though my pedantic side wants to argue for B being true as well.
