HELP ON PHYSICS HOMEWORK! (only stuck on these three)

Question

Estimate or measure the amount of time that passes between breaths when you are sitting at rest.
Convert the time from seconds into hours:
Convert the time from seconds into milliseconds (ms):

Convert the French speed limit of 140km/hr into mi/hr:

If the speed of your car increases by 10mi/hr every 2 seconds, how many mi/hr is the speed increasing every second? State your answer with the units mi/hr/s.u

Answer 1

Say the time you measure between breaths is 3 seconds.

Converting to hours:

3 seconds x 1 minute/60 seconds x 1 hour/60 minutes = 0.00083 hours = 8.3x10^-4 hours

 

Converting 3 seconds to milliseconds:

3 seconds x 1000 milliseconds/second = 3000 milliseconds

 

You should be able to do the conversions for speed.