Simple question?

[jazz]

I'm confused as to if the answer to this problem would be A)constant decrease or B)exponential decay. Albeit I knew that C)constant increase and D)exponential growth were probably wrong. Here is the question.
Tim is driving down the highway at a constant speed. Which of the following describes the amount of gas he has left in his tank?

Basically, I can't figure out what the difference between constant decrease or exponential decay in this problem would mean. Could anyone explain this to me?

 

[Bob Brown MSEE]

I'm confused as to if the answer to this problem would be A)constant decrease or B)exponential decay. Albeit I knew that C)constant increase and D)exponential growth were probably wrong. Here is the question.
Tim is driving down the highway at a constant speed. Which of the following describes the amount of gas he has left in his tank?

Basically, I can't figure out what the difference between constant decrease or exponential decay in this problem would mean. Could anyone explain this to me?

Its not surprising that you are confused. A) & B) depend upon what happens in the future.
You are correct that C) & D) are not possible but ...


None of them => If any variation in driving conditions other than
B) exponential decay => If hole in tank
A) constant decrease => conditions for EPA estimates to apply

ANSWER:
A) constant decrease => Assuming that the constant=zero and path is downhill all the way (Engine off)

 

[HallsofIvy]

I'm confused as to if the answer to this problem would be A)constant decrease or B)exponential decay. Albeit I knew that C)constant increase and D)exponential growth were probably wrong. Here is the question.
Tim is driving down the highway at a constant speed. Which of the following describes the amount of gas he has left in his tank?

Basically, I can't figure out what the difference between constant decrease or exponential decay in this problem would mean. Could anyone explain this to me?

There are a lot of minor things you have to ignore to answer this. For example, going uphill at a constant speed requires more gas than going downhill at the same speed. But assuming that the auto is moving at constant speed over a level road with no other complications, it should have a constant "miles per gallon" and since "miles per hour" is constant, we have constant "miles per gallon". That is, the "miles versus gallons" graph has constant slope and so is a straight line. There is a constant decrease in the amount of fuel.

 

[jazz]

Thank you.

There are a lot of minor things you have to ignore to answer this. For example, going uphill at a constant speed requires more gas than going downhill at the same speed. But assuming that the auto is moving at constant speed over a level road with no other complications, it should have a constant "miles per gallon" and since "miles per hour" is constant, we have constant "miles per gallon". That is, the "miles versus gallons" graph has constant slope and so is a straight line. There is a constant decrease in the amount of fuel.