During a race on an oval track, a sport car travels at an average speed of 220 km/hr.

(a) How far did it travel in 45 min ?

(b) Determine its average velocity at the end of its second lap. (4 km per lap)

###### Solution. Posted on Thursday, May 7, 2015.

(a) One hour equals 60 minutes, hence 45 minutes equals 45/60 = 0.75 hr.

We should use the following formula d = v*t , where d – distance, v – an average speed and t – time.

d = v*t = 220*0.75 = 165 km

(b) The average velocity is determined by the total displacement divided by the total time required to achieve that displacement. The car is right back where it was after every lap, so displacement is zero and the average velocity is zero as well.

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