+33615 a) Acceleration is change of velocity divided by time, so in first 15 mins the velocity changes from zero to 50 km/h. Since this takes 1/4 of an hour the acceleration is 50/(1/4) or 200 km/hr2.
b) The distance is given by the area under the velocity curve, so work out the areas of the separate sections and add them up. Make sure you express the time intervals in hours (or fractions of an hour).
c) The average speed of a section is given by (end velocity + start velocity)/2. Calculate this for each section then do a time weighted average of the five sections.
