Question

The distance, y, in miles, traveled by a car for a certain amount of time, x, in hours, is shown in the graph below:

A graph titled Motion of Car is shown with Time in hours labeled on x-axis and Distance from Starting Point in miles labeled on y-axis. The scale on the x-axis shows the numbers 1, 2, 3, 4, 5, 6, and the scale on the y-axis shows the numbers 0, 14, 28, 42, 56, 70, 84. There are three straight lines in the graph. The first line joins ordered pair 0, 0 with 3, 42. The second straight line joins 3,42 and 4,42 and the third straight line joins ordered pair 4,42 with the ordered pair 5,56.

Which of the following best describes the motion of the car shown?

It travels for 2 hours, then stops for 1 hour, and finally travels again for 5 hours.
It travels for 3 hours, then stops for 1 hour, and finally travels again for 1 hour.
It travels for 3 hours, then stops for 4 hours, and finally travels again for 5 hours.
It travels for 2 hours, then stops for 2 hours, and finally travels again for 1 hour.

Answer 1

It travels for 3 hours, then stops, for 1 hour, and finally travels again for 1 hour

Explanation:

for the first 3 hours (x terms in coordinates, 0 to 3) the car is gaining miles (the y terms in the coordinates given, 0 to 42), then from hour 3 to hour 4 (1 total hour) no miles are gained (y terms 42 to 42=no change/no gain), and the the miles change again from hour 4 to hour 5 (x terms again, 4 to 5), 1 total hour