Race Car Driver's Average speed

Click For Summary

Homework Help Overview

The problem involves calculating the average speed required for a race car driver to achieve a specific average speed over a series of laps, given the speed for the initial laps. The subject area pertains to kinematics and average speed calculations.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between average speed, distance, and time, with one suggesting the use of algebra to derive the necessary speed for the final lap. Another participant outlines the total distance and time constraints based on the average speed requirement.

Discussion Status

The discussion includes various approaches to the problem, with some participants providing insights into the calculations needed to determine the speed for the last lap. There is no explicit consensus, but productive lines of reasoning have been shared.

Contextual Notes

Participants are working with the assumption that the total distance for the laps is consistent and that the average speed must meet a specific target. The discussion also reflects on the time constraints imposed by the average speeds of the earlier laps.

Pioneer98
Messages
19
Reaction score
0
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
 
Physics news on Phys.org
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.
 
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?
 
Okay I got it thanks a lot for the help :)
 

Similar threads

How Do You Calculate Race Car Acceleration and Power Output?
  • · Replies 20 ·
Replies
20
Views
2K
How Fast Does the Racecar Driver Have to Drive?
  • · Replies 19 ·
Replies
19
Views
4K
What is the required speed for the last 2 laps to qualify for the race?
  • · Replies 1 ·
Replies
1
Views
2K
Momentum: instantaneous or average?
  • · Replies 9 ·
Replies
9
Views
1K
What Is the Average Angular Speed of a Race Car on a Circular Track?
  • · Replies 1 ·
Replies
1
Views
2K
Problem Driver Must Average 337.5 km/h for Last 4 Laps
  • · Replies 4 ·
Replies
4
Views
2K
Calculate the average speed and average velocity
  • · Replies 2 ·
Replies
2
Views
2K
Calculating Average Speed: Physics Homework Problem
  • · Replies 13 ·
Replies
13
Views
2K
How Fast Must the Race Car Go in the Last 2 Laps to Qualify?
  • · Replies 1 ·
Replies
1
Views
2K
What are the average speed formulas needed to solve this problem?
  • · Replies 5 ·
Replies
5
Views
5K