How do you determine the acceleration of an object?

A. Divide the change in velocity by the time interval

B. Subtract the starting velocity from the ending velocity

C. Multiply the change in velocity by the time interval

D. Determine the average velocity and divide by the distance traveled

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

Answerlosing electrons;