Dimensional analysis and exponents

In summary, the conversation discusses the formula for the period of a simple pendulum and finding the powers p and q required for dimensional consistency. The conversation also mentions a teacher who does not explain things before assigning homework and asks for help.
  • #1
addedline8
5
0
I decided to take physics this year, my senior year in high school, and my teacher has decided he isn't going to explain things before he assigns us homework. Any and all help is appreciated.

1. The period T of a simple pendulum is the amount of time required for it to undergo one complete oscillation. If the length of the pendulum is L and the acceleration of gravity is g, then T is given by:
2. T = 2 (pi) Lp gq
3. T = 2 (pi) Lp (L/T2)q

Find the powers p and q required for dimensional consistency.
 
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  • #2
Hint. L is in meters, g is in meter/second^2 and period T is in seconds. Now just do the algebra.
 
  • #3
addedline8 said:
I decided to take physics this year, my senior year in high school, and my teacher has decided he isn't going to explain things before he assigns us homework. Any and all help is appreciated.

1. The period T of a simple pendulum is the amount of time required for it to undergo one complete oscillation. If the length of the pendulum is L and the acceleration of gravity is g, then T is given by:



2. T = 2 (pi) Lp gq



3. T = 2 (pi) Lp (L/T2)q

Find the powers p and q required for dimensional consistency.

keep going the way you have started..

T = 2 (pi) Lp (L/T2)q

T = 2 (pi) Lp Lq/T2q

T = 2 (pi) Lp+q.T -2q

Now compare dimensions left and right.

What must -2q equal?

What must p+q equal?
 
  • #4
Thanks a lot guys. I appreciate the help.
 
  • #5


I understand that dimensional analysis is a crucial tool in physics to ensure that equations and calculations are mathematically consistent and physically meaningful. It involves breaking down physical quantities into their fundamental units and using them to determine the powers of each variable in an equation.

In the given equation for the period of a simple pendulum, we can see that the length L is measured in meters (m) and the acceleration of gravity g is measured in meters per second squared (m/s^2). Therefore, the powers p and q must be chosen in a way that the units on both sides of the equation are consistent.

For the first equation, the powers p and q should be 0 and 1, respectively, to ensure that the units on both sides are meters (m).

For the second equation, the powers p and q should be 1 and -1, respectively, to ensure that the units on both sides are seconds (s).

For the third equation, the powers p and q should be 1 and -2, respectively, to ensure that the units on both sides are seconds squared (s^2).

It is important to note that these powers are not arbitrary and are determined based on the units of the variables in the equation. I would suggest discussing this topic with your teacher to gain a better understanding of dimensional analysis and how it applies to physics equations. Additionally, there are many online resources and tutorials available that can help you practice and improve your skills in this area. Good luck with your physics studies!
 

FAQ: Dimensional analysis and exponents

What is dimensional analysis?

Dimensional analysis is a method used in science and engineering to convert units of measurement and determine the relationships between different physical quantities.

How is dimensional analysis used in scientific calculations?

Dimensional analysis is used to ensure that the units in a calculation are consistent and to check for any errors in the equation. It also helps to simplify complex equations and make them more manageable.

What is the importance of using exponents in dimensional analysis?

Exponents are used in dimensional analysis to represent the powers of units in an equation. This allows for easier manipulation and conversion of units, as well as providing a more concise representation of the equation.

Can dimensional analysis be used in all scientific fields?

Yes, dimensional analysis is a universal method that can be applied in all scientific fields, including physics, chemistry, biology, and engineering.

How can dimensional analysis be applied in real-world scenarios?

Dimensional analysis can be applied in many real-world scenarios, such as converting units of measurement, calculating dosages in medicine, and determining the relationships between physical quantities in engineering projects.

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