Why do the units for time appear twice in the units for acceleration

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Homework Help Overview

The discussion revolves around the concept of acceleration in physics, specifically addressing why time appears twice in the units for acceleration. Participants explore the relationship between velocity, time, and acceleration, while also attempting to clarify their understanding of the equations involved.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants raise questions about the units of acceleration and their derivation from velocity and time. There are attempts to clarify the equations used for calculating acceleration and the implications of the units involved.

Discussion Status

The discussion is ongoing, with participants seeking clarification on their understanding of the equations and the underlying concepts. Some guidance has been offered regarding the definitions of velocity and acceleration, but there is no explicit consensus on the correctness of the answers provided.

Contextual Notes

Participants express confusion about the formulation of equations and the interpretation of terms. There is a focus on ensuring that the mathematical expressions are correctly understood and applied.

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1. why do the units for time appear twice in the units for acceleration
2. a = v/t - v1-vo/t1-t0
3. once for speed change and once for time change.

1. what is the acceleration of a car that travels in a straight line at a constant speed of 27 m/s?
2. 27m/s / 10s
3. 2.7m
 
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mppaki said:
1. why do the units for time appear twice in the units for acceleration
2. a = v/t - v1-vo/t1-t0
3. once for speed change and once for time change.

1. what is the acceleration of a car that travels in a straight line at a constant speed of 27 m/s?
2. 27m/s / 10s
3. 2.7m

Is this:

1. why do the units for time appear twice in the units for acceleration

your first question?

Is this:

2. a = v/t - v1-vo/t1-t0

a possible answer?

It's not clear what you would like help with. Identify your question, then show your attempt to answer it.
 
a = v/t = v1-v0/t1-t0

i just want to know if i got the right answer or not
 
mppaki said:
a = v/t = v1-v0/t1-t0

i just want to know if i got the right answer or not

[tex]a=\frac{\Delta v}{\Delta t}= \frac{v_{f}-v_{o}}{t_{f}-t_{o}}[/tex]

you can't write it like "v1-v0/t1-t0" this means that v1 minus (vo over t1) minus t0.
 
Bright Wang said:
[tex]a=\frac{\Delta v}{\Delta t}= \frac{v_{f}-v_{o}}{t_{f}-t_{o}}[/tex]

you can't write it like "v1-v0/t1-t0" this means that v1 minus (vo over t1) minus t0.


yeah that's the equation i thought would relate, but are my answer correct?
 
What exactly is your question?
 
both number 1
 
mppaki said:
1. why do the units for time appear twice in the units for acceleration
2. a = v/t - v1-vo/t1-t0
3. once for speed change and once for time change.

1. what is the acceleration of a car that travels in a straight line at a constant speed of 27 m/s?
2. 27m/s / 10s
3. 2.7m

Okay, now that you have told us that Number 1 is the question in both cases, we can help you. First, your answer to question 1 is not correct. Think about the definitions. Velocity is change in position divided by change in time so the units are length/time or

[tex]V = \frac{L}{T}[/tex]

Now acceleration is change in velocity divided by time. Take the equation I just wrote and do the algebra. What do you see?

For the second question. What is the adjective modifying the word speed? What is the definition of velocity that I just wrote? Put those tow ideas together and what do you get?

Hint: With physics sometime it's useful to ask "What does it mean?" and then go back and look at the definitions.
 

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