Which of the following graphs applies to each situation? Each graph shows the behaviour of two objects; east is in the direction of positive d. (E.g., if graph A applies to situation 1. and C to the rest, enter ACCCCC) 1) An upward moving elevator colliding with a downward mov- ing elevator. 2) An eastward moving truck applying the brakes and a west- ward moving truck speeding up. 3) A car moving at a steady speed is overtaken by a police car starting from rest. 4) A car, initially at rest, accelerating and a car moving ini- tially at constant speed applying the brakes until it stops. 5) An initially moving truck speeding up eastward and a west- ward moving truck slowing down. 6) A race car speeding up to match the speed of a second race car.

Which of the following graphs applies to each situation? Each graph shows the behaviour of two objects; east is in the direction of positive d. (E.g., if graph A applies to situation 1. and C to the rest, enter ACCCCC) 1) An upward moving elevator colliding with a downward mov- ing elevator. 2) An eastward moving truck applying the brakes and a west- ward moving truck speeding up. 3) A car moving at a steady speed is overtaken by a police car starting from rest. 4) A car, initially at rest, accelerating and a car moving ini- tially at constant speed applying the brakes until it stops. 5) An initially moving truck speeding up eastward and a west- ward moving truck slowing down. 6) A race car speeding up to match the speed of a second race car.