Use the vocabulary words from "Read It" to complete the following sentences.
When an object changes its velocity then it has an
(4). __. But what can change an object's motion?
Usually motion is changed with a (5), which is a
push or a pull on an object. When we add up all the
forces on an object we find the (6)_ . When all the
forces add up and are the same amount in both
directions, then we say that there is a (7).
When all the forces add up and are different amounts
in both directions, then we say there is an (8).