6. A bus travelling at an average speed of 30 km/h leaves Norwich for Thetford at 5.00 p.m. A woman driving a car at 45 km/h leaves Thetford for Norwich at 5.30 p.m. It is 50 km from Norwich to Thetford on the road that they are both using. Draw a distance time graph showing both journeys Use your graph to estimate the time at which they passed each other. (iii) How far from Norwich were they when this happened? (iv) What factors might affect the accuracy of your estimates in (ii) and (iii)