Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
A force is a or pull between any objects and are measured in the metric unit of a . Forces are vectors, which means that they have both an amount and a . When two or more act upon an object in the direction the amounts are added together. When two or more forces act in the opposite direction the amounts are from each other. If the two forces are the exact same amount in the opposite direction they will equal Newtons and are called forces, if not they are called unbalanced forces. forces will always cause a change in which is called .