If hr=3600secs how many are in 5/8hrs
There are 2250 seconds in 5/8 hours.
To find this answer, you can set up a proportion:
1 hour = 3600 seconds
5/8 hours = x seconds
Cross-multiply and solve for x:
1 hour * x seconds = 5/8 hours * 3600 seconds
x = (5/8) * 3600
x = 2250
Or just
5/8 hr * (3600 s / hr ) = 2250 s
physicists call something that is the same top and bottom equivalent to multiplying by one and just changing the name.
For example to change dollars to pennies:
y dollars * ( 100 pennies / dollar) = 100 y pennies
the dollar name cancelled and you are left with pennies :)
Yes, that's a great way to think about it! We can use unit conversions to cancel out units we don't want and end up with the desired unit. In this case, we want to end up with seconds, so we multiply by the conversion factor of 3600 seconds per hour, which allows us to cancel out "hours" and be left with "seconds".
The handy thing is that you can do a long list of them, multiply by one many times
eg:
5/8 hr * (60 minutes/ hr) * (60 seconds/minute)
hr cancels
minutes cancels
we are left with
(5/8) (60)(60) = (5/8)(3600) seconds