1. A thunderclap is heard 7.0 s after a lightning flash is seen. If the speed of sound is 340 ms1, how far away in km was the lightning flash. 2. Light from the Sun takes 8 minutes and 18 seconds to reach Earth. If the speed of light is 3.0 x 108 ms', what is the distance between Earth and the Sun in km? 3. Sally walks 150 m north at 1.0 ms' and then 200m east at 2.0 ms1 (a) For what length of time did she walk? (b) Use a vector diagram to calculate Sally's displacement. (HINT: calculate displacements for each motion first!) Diagram Calculation (c) Compare Sally's average speed and her average velocity. 4. Sketch the following graphs: (a) A velocity time graph for a car travellinmg at a constant velocity along a straight road. (b) A velocity time graph for a ball dropped from a one metre height and then bounces once. ( consider upwards velocity to be positive and downwards negative) (c) A speed time graph for this object over the same time period. (d) A velocity-time graph for a car that accelerates from start to reach a constant velocity in 10 s. ( e) A speed-time graph for a car that slows down from 60 km per hour to a halt over a period of 10 seconds. 5. A fighter plane lands on an aircraft carrier at a speed of 300 km per hour takes 25 seconds to come to rest. (a) Determine its landing speed in ms1 (b) Determine its average deceleration. (c) When the same plane takes off, it accelerates from rest at 9.9 ms2 . If it takes 2.3 seconds to reach its take off velocity: (i) Determine this velocity. (ii) Calculate the minimum length of runway it must have to take off