Acceleration units

[Vaidoras]

5 km/h*sec

-Is how my textbook gives equation for acceleration which confuses me because the way I understand, it should be:

5 km/h/sec

 

the textbook equation would read - five kilometers per hour each second

while mine would read - five kilometer per hour per second

 

Is there any difference between them that I am missing, and do you think my professor would take points off if i do it later way?

 

I am in a course where I teach myself and turn my work in, and semester has not even began yet so i can't ask directly and this is just a litlle thing that wont leave my mind

[Cap'n Refsmmat]

Acceleration should always be in units of [math]\frac{\text{length}}{\text{time}\times\text{time}}[/math] or [math]\frac{\text{length}}{(\text{time})^2}[/math]

[Vaidoras]

Acceleration = change in speed/time interval

Since change in speed will be expressed in distance/time it’s correct to say that

Acceleration = distance/time/time

So if a question asks “what is acceleration of something” I should say “it’s X meters/second/second”

Yes, no ?

[Klaynos]

I suspect what they mean is:

 

5km/(h*s)

 

Which would be correct, if a slightly weird unit choice.

 

Vaidoras, acceleration = change in velocity / change in time

 

Velocity instead of speed is important because it forces us to have to work in vectors...

[Gilded]

So if a question asks “what is acceleration of something” I should say “it’s X meters/second/second”

Yes, no ?

 

Don't say that in a mathematical way though, it would mean that "acceleration = velocity". One pretty straightforward and correct answer to a question like that is "the rate of change of velocity".

[Air]

The standard SI unit for acceleration is [math]\mathrm{ms}^{-2} = \frac{\mathrm{m}}{\mathrm{s}^2}[/math].

[Sisyphus]

It's saying the exact same thing, but the way your textbook has it is still preferable, because it's simpler. Your way requires parentheses and a second solidus. In order of increasing simplicity:

 

(m/s)/s = m/(s*s) = m/s^2 = ms^-2

 

Similarly, (km/s)/h = km/(s*h)

[Vaidoras]

Thanks for all of your input, I can be a real stickler over little things when it comes to math so you've saved me some headaches,

I finally get it now and decided to use v/t^-2 since I can get it around my head fastest beside v/t/t and it's less writing and confusion.

 

Don't say that in a mathematical way though, it would mean that "acceleration = velocity". One pretty straightforward and correct answer to a question like that is "the rate of change of velocity".

 

sorry, i really don't get what you're saying

what do you mean mathematical way?

how is that saying that acceleration = velocity?

and "the rate of change of velocity" is definition of acceleration so It's probably easier to just say acceleration. ?

[Cap'n Refsmmat]

Careful there. v/t^-2 = vt^2. You meant vt^-2 or v/t². You need to remember how negative exponents work.

[Gilded]

sorry, i really don't get what you're saying

what do you mean mathematical way?

 

"meters/seconds/seconds" just seemed like something that might cause confusion if you're asked to describe acceleration mathematically.

 

and "the rate of change of velocity" is definition of acceleration so It's probably easier to just say acceleration. ?

 

Didn't you ask what you should answer if you're asked what acceleration is or what it means? "It's acceleration" isn't really sufficient in that case.