What is most often given a value of zero to describe an object's position on a straight line? O displacement
O reference point
O distance
O ending location

O reference point

Explanation:

A reference point is often given the value of zero to describe an object position on a straight line, or when it didn't move. If the object doesn't move, that means that there is no displacement, and it is a reference point. The answer to the question is reference point.

what was the acceleration of the 2 kg cart?

⇒ 16.0 cm/s2

what was the acceleration of the 4 kg cart?

⇒ 8.1 cm/s2

what was the acceleration of the 6 kg cart?

⇒ 5.3 cm/s2

explanation:

newton's third law, for every action there is an equal and opposite reaction.