[camerono]

I am new to physics and cannot figure out what to do with the following problem. It seems simple but I am not sure if I am doing it correctly. Here it is:
If someone travels 252.4 km/hour, how long will it take them to travel 100m?
I am thinking I should just divide using 1000m to get my speed per meter and set up my problem like this:
Time = distance/speed

T= 1000m/252.4 = 3.961965135
then I would need to divide this by 10 to get it to 100 m
3.961965135/10 = .3960965135 seconds.

Can anyone tell me if this correct, and if not, what I need to do to find the answer?

Thank you!

[Capuchin]

Before you can do anything, since you want the answer in seconds, and the distance you are measuring is in meters, you want a speed in meters/second in order to get a meaningful result.

To convert from km to m you need to multiply by 1000, and to convert from /hour to /s you need to divide by 60*60

Does that help?

[camerono]

Thank you. I am not sure if this is how I am supposed to continue our dialog. This is my first visit to this site. From what you said that means I need to:
d= 100/252,400 = 3.961965134
then 3.961965134/3600 = 1.100545870 (the number comtines but I am not sure how much to include).
would this be correct that it would take him 1.1 etc seconds to go 100m?

[Capuchin]

No, you didn't do what I said :)

You multiply the speed by 1000 to change from km to m, so this gives 252400m/h

Then you divide by 3600 to get is in per second, so this gives 70.1111111 m/s

Now you can use this speed to work out the time.

You should always quote your answer to the same accuracy as the initial data. So your initial data was to 0 decimal places or 3 significant figures, so you should give your answer probably to a few significant figures.

[camerono]

thank you!
so then I would need to:
T= d/s = 100m/70.111 = 1.4263
is that correct?
sorry I am so slow at this

[Capuchin]

Yup, but I would just state it as 1.4 seconds or maybe 1.43 seconds.

[camerono]

So would it be correct to say that it would take 1.43 seconds to travel 100 m?

For future reference, do you know a formula to check my work so I can make sure I get the correct answer?

[CaptainRich]

You beat me!
I'm not at all math-letic, but I tried to follow along.
You left me at the pencil sharpener.
You've got perseverance.

[Capuchin]

Yes, that's correct to say.

To check your work you just need to work on making logical steps. You need to convert into the right units first, then do any calculation you need to. There isn't really any way you can check very easily.

[camerono]

I really appreciate your patience with me.! Thank you!

[Capuchin]

Any time :)

It's nice to get someone who wants to learn, rather than someone who just wants the answer :)