[ 447 ] Physical Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • The graph represents the motion of a remote-controlled car. The car’s acceleration, or change in velocity, is indicated by the slope of the graph. Velocity (m/s) 60 50 40 30 20 10 10 20 30 40 50 60 70 80 90 Time (sec) During which time period was the car experiencing a constant positive acceleration? A. between 0 and 20 seconds B. between 20 and 40 seconds C. between 40 and 50 seconds D. between 50 and 90 seconds