Race Car Driver's Average speed

[Pioneer98]

A race car driver must average 200.0 km/h over the course of a time trial lasting ten laps. If the first nine laps were done at 198.0 km/h , what average speed must be maintained for the last lap?

Avg Speed=Distance traveled/Time

218 km/h, I averaged the first 9 laps at 198 and plugged the speed for the tenth lap in until I got an average speed of 200 km/h

 

[BruceW]

I don't think the answer is 218 km/h, but it is close to that. You can work out the answer using algebra. The key equation is Avg Speed=Distance traveled/Time (which you have got written down). You need to think how to write out the 'Time' in the denominator.

 

[HallsofIvy]

In order to have an average speed of at least 200 kmph, the driver must complete all 10 laps, with a length lf r km, so a total distance of 10r km, in 10r/200= (1/20)r hrs.

If he averaged 198 km/hr for the first 9r km then he must have taken 9r/198= r/22 hrs. How much time does he have left for the tenth lap?

 

[Pioneer98]

Okay I got it thanks a lot for the help :)

 

[asteriatic]

. The driver must maintain an average speed of 218 km/h for the last lap in order to reach an overall average speed of 200 km/h for the entire time trial. This means that the driver must go faster than their previous laps in order to make up for the slower speeds in the first nine laps. It is important for a race car driver to maintain a consistent and high average speed in order to be successful in a time trial. Achieving this requires a combination of skill, strategy, and a well-maintained car.