Use the graph of distance versus time to complete the
sentences.
the cars on the higher track travel
the cars on the lower track, in
the same time.
this means that the cars on the higher track have a
average speed than those on the lower track.
this is demonstrated by the
of the
higher track line being greater than the slope of the
lower track line.

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?