/sci/ - Science & Math

[Anonymous No.3344678]

So I have a question, no its not homework, In my free time on my ship I'm learning basic physics.

acceleration = Change of velocity / Time.

I understand this when it comes to M/s

However, when I convert this over to MPH, I get a little lost. After I get my answer I should divide by 60 *which would be minutes* and then divide by another 60 * which would be seconds* and then multiply the number I receive by the number of seconds that it has traveled.

Correct?

[Anonymous No.3344702]

A little help for a military bro?

[EK !EKFQOBUFnQ No.3344707]

meters per second into miles per hour?
multiply by 3600/1609

[Anonymous No.3344732]

Think about it like fractions.

If there are 30 meters per second, that is 30/1 m/s, multiply by 1/1609 mi/meter, and then 3600/1 s/h, so then you get (30*3600)/1609 mi/h

[Anonymous No.3344738]

The units of velocity are M/s

The units of Acceleration are M/s^2

When converting from one unit to another it's easiest to think of which units is the "greater" as in a mile covers a greater distance than a meter.

So when you do you calculations, you know that if you have an amount meters you want into miles, you have to get a smaller number because meters are less than miles (by a factor ~1600).

Say 20 M/s into MpH:

First off M/s into Miles/s:

20 M/s / 1600 = 0.0125

Then Miles/s into Miles/hour:

0.0125 Miles/s * 60 (minutes) * 60 (hours) = 45 MpH

Again, you know you need to get a greater value because seconds are less than hours. If dividing doesn't give you that, try multiplying and eventually you'll get the hang of it just by reading the problem. Then it'll feel natural

[Anonymous No.3344748]

>>3344707


sorry I might have done it wrong.

Here I'll post the two ways I have it.

I'm doing very simple ways of it to try and see if I can get it right first.

(Q)A = 1(m/s) / 20(s)
(A)A = .05M/s(squared)

Take the same problem into a steady velocity increase. so D = VT

(Q)D = .50 x 20
(A)D = 10M

however when I try and do this in MPH I get lost on the D = VT part.

(Q)A = 10(Mph) / 5(s)
(A)A = 2 Mph(squared)

Here is where I get lost.

(Q)D = 5(Mph) x 5(s)
(A)D =

I keep getting it wrong right here. I need to know if I should do this.

5(Mph) which is the average, should be divided by 60 (which would be minutes in a hour) and then by 60 (which would be seconds in a minute) and then times 5 (for the number of seconds traveled)

so this.

5(Mph) / 60 = A / 60 = B x 5 = D

This is the best I can word this sorry if its still not clear.

[EK !EKFQOBUFnQ No.3344768]

>>3344748
>(Q)A = 10(Mph) / 5(s)
>(A)A = 2 Mph(squared)

looks like you're mixing units. you cant have miles per hour per second and then call it miles per hour squared.

[Anonymous No.3344790]

>>3344768

shit, I just noticed that. I guess I've been away from math longer then I thought.

Alright that is probably part of my problem.

The book I'm reading is working in M/s and I kinda jumped ahead to see what I could do and I guess I really screwed it up.

took 3 posts to get this in the right thread. fuck me.

[EK !EKFQOBUFnQ No.3344810]

>>3344790
http://www.wolframalpha.com/input/?i=meters+per+second+squared+into+miles+per+hour+squared

[Anonymous No.3344809]

>>3344768

Alright so now that I see what I did, would this be right?

(Q)A = 10(Mi) / 5(s)
(A)A = 2 Mi/s(squared)

Here is where I get lost.

(Q)D = 5(Mi) x 5(s)
(A)D = 25(Mi)

Fuck I think that's right.

[Anonymous No.3344836]

Someone show him how to write out conversions where like you divide the units you start with by the same units so it cancels and shit.

If you're notation is awesome you will get it correct everytime.

[Anonymous No.3344839]

>>3344810

Just so you know I'm not trying to get meters into miles, or miles into meters.

I just needed to know how to set up Miles/second

I had fucked up and put Mph/second, which I don't know why I didn't catch when I set up the problems.

[EK !EKFQOBUFnQ No.3344849]

>>3344839
sorry? i dont think i understand. what is the conversion you are doing?
just meters per second into miles per second?
thats a simple division by how many meters there are in a mile, which is 1609 IIRC.

[Anonymous No.3344856]

>>3344839

pretty much what I did was fuck up all my math by simply putting MPH instead of Mi (miles)

The only reason I said M/s was because I could do the problems with those numbers but not miles.

Anyways, I got it now, thanks for the help. even thought it was directly with what you answered but more like what you noticed.

[EK !EKFQOBUFnQ No.3344860]

>>3344856
erm, okay. im slightly confused, but as long as you've figured it out, thats good.

[Anonymous No.3344865]

>>3344849

No, I just said I was able to do A = CoV/T in both Miles/s and Meters/s

but I could only get D = VT with Meters/s not Miles/s

I can see how you thought I was trying to convert Meters to Miles though. It was bad wording on my part.

[Anonymous No.3344883]

>>3344839

[Anonymous No.3344927]

>>3344883


yea I feel stupid right now because I fucked up and put xx(Mph) / xx(s)

when all I needed to do was xx(Mi) / xx(s)

it was just be not paying attention and then confusing myself trying to break MPH down to s in a very long and stupid way.