You are asked to calculate an object's velocity, in order to do so you must know the object's

There are multiple ways to know some object velocity:

One is knowing the distance that it travels in some amount of time, you can do the quotient (because velocity is a measure of distance over time) and obtaining the mean velocity of the object in that period of time.

Other way is knowing the acceleration of the object for a certain time, and the initial velocity of the object, we know that if we integrate the acceleration over time we get the velocity, and when we integrate, we must add a constant of integration, which is the initial velocity of the object.

answer: strength i guess

explanation:

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

hope this !