MATH
posted by Anonymous .
I am working on Measurements and it is one of the most difficult things for me to do. Topics include the SI measurement, Imperial Measurement, and Converting between SI and Imperial Systems.
I would like to do some review on this and would like to know a easier way to all problems.
Montgomery ran 100m in 9.78s. What was the runner's speed in kilometres per hour?
How do I do this? Do I convert metres to kilometres first? How do I convert seconds to hours? I just don't get it . Can someone please provide me with clarification.

MATH 
Reiny
maybe this will make sense to you .....
100 m = .1 km
and 1 sec = 1/(60x60) or 1/3600 hour
so 100 m/9.78 sec
= .1 km/(9.78 x 1/3600) hr
= 36.8 km/hr
or look at it this way ...
there are 3600 seconds in 1 hour.
so by dividing 3600 by 9.78 we would get 368 legs of 100 m, but 10 of those 100 stretches make 1 km, so divide 368 by 10 to find the number of km
or 36.8 km/hr
I would simply form a ratio using the same units the same units
.1 km/9.78 sec = xkm/3600 sec
cross multiply
9.78x = .1(3600)
x = 360/9.78
x = 36.8
so x = 36.8 km/3600 sec
= 36.8 km/hr 
MATH 
Anonymous
That does make a lot of sense, thank you very much Reiny!
Respond to this Question
Similar Questions

Measurement
Are SI measurements always larger than Imperial measurements? 
worldhistory 6th grade
what was the key difference between the government of the roman republic and the government of imperial rome? 
Social Studies
What effect did John Hay's open door policy letters have on the imperial powers of Britain, France, Germany, Russia and Japan? 
Social studies
what effect did john hay's open door policy letters have on the imperial powers of britain france germany russia and japan? 
social studies
What effect did John Hay's open door policy letters have on the imperial powers of Britain, France, Germany, Russia and Japan? 
Social Studies
I'm majorly behind in school right now and I really want to get caught up, but I need some help on this assignment. 1.What effect did John Hay's open door policy letters have on the imperial powers of Britain,France,Germany,Russia, … 
Social Studies
I NEED HELP QUICK!!!! what effect did John Hay's open door policy letters have on the imperial powers of Britain France Germany Russia and Japan? 
U.S. History
What effect did John Hay’s open door policy letters have on the imperial powers of Britain, France, Germany, Russia, and Japan? 
History
Which examines the relationship between the colonies and their imperial governments? 
histroy
Which evaluates the economic dependence that occurred between imperial governments and their colonies?