Calculating Car Speed: Melbourne to Moe

  • Thread starter ahoy hoy
  • Start date
  • Tags
    Car Speed
In summary, the question asks for the least number of times the speedometer reads 80 km/hr. Assuming a smooth trip and no intermediate stoppages, the car should travel at least twice.
  • #1
ahoy hoy
14
0
im stuck as to how to approach this in a mathematical way..
"a car travels from melbourne to moe at an average speed of 80km/h. what is least number of times the speedometer reads 80km/hr ? Explain".
thanks.
 
Physics news on Phys.org
  • #2
ok... sounds like a "trick" question... I guess if you want to reach an average of 80, the speedometer must at some point get above 80, taking into account the fact that you will have to start from rest (ie. traveling at below 80 at some stage) and slow down or stop at intersection etc... so I would say at least twice assuming a smooth ride with no intermediate stoppages ...
 
  • #3
mm i get wat u mean.
i think its safe to assume that question is gaylord.
thanks heaps.
 
  • #4
Do they give you how long it took or the distance at all?

I'm thinking it may be possible to use the mean value theorem. But then you would need a position function and the time it took to get there.
 
  • #5
nothing. i don't think they expect us to go out of our way and calculate distance between the two well known suburbs. I am ok with settling with the logic of mjsd
 
  • #6
It is indeed a mean value theorem problem. Let x be time, and f(x) be the distance traveled so far. Suppose that the car starts at t=a, and reaches the destination at t=b.

What is (f(b)-f(a))/(b-a)

What is f'(x)?
 
  • #7
In a very unrealistic way of driving your car, the least number of times should be 1 i think >.<

Maybe the 2nd time msjd was talking about is when he's arrived at the destination? The question just says traveled to that place, doesn't have to stop there.
 
  • #8
Gib Z said:
In a very unrealistic way of driving your car, the least number of times should be 1 i think >.<

Maybe the 2nd time msjd was talking about is when he's arrived at the destination? The question just says traveled to that place, doesn't have to stop there.


yes the answer's definitely 1 because you could simply go 79 for most of the trip and then cross over into high speeds to reach an average of 80 in the last minute. How to tie this rigorously to the MVT(which is what others are saying and was my intuition) is not immediately clear to me, but it makes intuitive sense.
 
  • #9
*sigh*

How could I possibly have made it any clearer without giving away the answer?
 
  • #10
Well this isn't the homework forum, not harm in doing so...
 
  • #11
Just because this thread is not in the homework forum doesn't mean its not someone's homework problem.
 

FAQ: Calculating Car Speed: Melbourne to Moe

How do you calculate the speed of a car from Melbourne to Moe?

To calculate the speed of a car from Melbourne to Moe, you would need to know the distance between the two locations and the time it took for the car to travel that distance. The formula for calculating speed is distance divided by time. So for example, if the distance between Melbourne and Moe is 150 kilometers and it took the car 2 hours to travel that distance, the speed would be 75 kilometers per hour.

Is there an average speed for the Melbourne to Moe route?

There is no specific average speed for the Melbourne to Moe route as it can vary depending on factors such as traffic, road conditions, and the type of vehicle being used. However, according to Google Maps, the estimated driving time for this route is around 2 hours and 30 minutes, which would give an average speed of 60 kilometers per hour.

How accurate are speed calculations for long distances like Melbourne to Moe?

The accuracy of speed calculations for long distances like Melbourne to Moe depends on the accuracy of the distance and time measurements. If the distance and time are measured correctly, the speed calculation should be accurate. However, external factors such as traffic and road conditions can also affect the accuracy of the calculation.

Can you use different units for calculating car speed?

Yes, you can use different units for calculating car speed. The most commonly used units are kilometers per hour (km/h) and miles per hour (mph). However, you can also use meters per second (m/s) or even feet per second (ft/s) if you prefer. Just make sure to use consistent units for both distance and time in the calculation.

Is it possible to calculate the average speed for multiple stops along the Melbourne to Moe route?

Yes, it is possible to calculate the average speed for multiple stops along the Melbourne to Moe route. You would need to measure the distance and time for each individual stop and then calculate the average speed for the entire route using the same formula of distance divided by time. Keep in mind that the average speed may vary depending on the distance and time taken for each stop.

Similar threads

I Twin Paradox: Calculating Stan's Time Elapsed According to Moe
Replies
20
Views
2K
Acellerating car vs constant speed car
Replies
9
Views
2K
I Car low average speed vs aero drag relation
Replies
4
Views
1K
Quick Motion Question - Rejogging memory after a while.
Replies
13
Views
2K
I Limits confusion -- What is meant by "instantaneous rate of change"?
Replies
18
Views
2K
Questions about speed and motion of a toy car on a conveyor belt
Replies
11
Views
1K
Calculating Relative Velocity: Train vs. Car Collision
Replies
3
Views
1K
I Paradox of the car and the driver in SR
Replies
23
Views
1K
Circular Motion Application Question
Replies
1
Views
1K
How Do You Calculate Tractive Force for Accelerating a Car?
2
Replies
40
Views
4K

Hot Threads

Recent Insights

Back
Top