Dimensional Analysis Question?

In summary, the speed of an automobile, given by v = at2 + bt3, has units of m/s and the constants a and b have units of m/s^3 and m/s^4, respectively. This question is likely testing your understanding of dimensional analysis.
  • #1
Qube
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Homework Statement



During a short interval of time the speed v in m/s of an automobile is given by v = at2 + bt3,where the time t is in seconds and a and b are constants. The units of a and b are respectively:

Homework Equations



I'm assuming that dimensional analysis is needed for this question. This seems like an odd question since units are in meters per second qubed and meters per second raised to the fourth power.

The Attempt at a Solution



I know the units on the left hand side have to be m/s since it's velocity on the left and so the units on the right hand side must also be m/s. So the units of a and b should be m/s^3 and m/s^4, respectively.

Am I just overthinking this problem or is it really that easy? Is this problem just testing to see if we have any common sense and can do dimensional analysis?
 
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  • #2
Qube said:
So the units of a and b should be m/s^3 and m/s^4, respectively.


It seems to me that you understand it. I believe the problem is just attempting to familiarize you with the use. If that is t^2 and t^3, then you are correct.
 
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Related to Dimensional Analysis Question?

1. What is dimensional analysis and why is it important in science?

Dimensional analysis is a problem-solving method in which physical quantities are expressed in terms of their fundamental dimensions. It is important in science because it allows for the conversion of units, the comparison of different systems of measurement, and the identification of relationships between different physical quantities.

2. How do you perform dimensional analysis?

To perform dimensional analysis, you must first identify the given quantity and its units. Then, you must determine the desired quantity and its units. Next, you use conversion factors or unit equivalencies to cancel out the given units and arrive at the desired units. Finally, you perform the necessary mathematical operations to find the numerical value of the desired quantity.

3. Can dimensional analysis be used in all branches of science?

Yes, dimensional analysis can be used in all branches of science, including physics, chemistry, biology, and engineering. It is a universal problem-solving method that is based on fundamental principles of measurement and unit conversions.

4. What are the benefits of using dimensional analysis?

There are several benefits of using dimensional analysis, including the ability to check the correctness of equations, the simplification of complex problems, and the elimination of errors due to unit conversions. It also allows for the comparison of different systems of measurement and the identification of relationships between physical quantities.

5. Are there any limitations or drawbacks to using dimensional analysis?

While dimensional analysis is a powerful problem-solving tool, it does have some limitations. It assumes that the given equations are dimensionally consistent, and it does not take into account any non-linear relationships between physical quantities. Additionally, it may not be suitable for extremely complex problems that involve multiple steps and conversions.

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