A driving instructor gives a student a sudden order to stop the car in the shortest possible time. Fig. 2 shows the speed-time graph of the motion of the car from the moment the order is given. The order to stop is given at time t = 0 s. (a) State the speed of the car at t = 0 s. speed .

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.