# Convert Units of Velocity

Questions, with answers, on how to convert from one unit of velocity (speed) to another. For the lengths, both metric and imperial units are used.

Both time and length conversions are needed in order to convert velocity or speed units. The time conversion is shown below and the length conversion is in a table in this site.

Time Conversion.
1 hour = 60 minutes
1 minute = 60 seconds
1 hour = 3600 seconds
1 minute = 1/60 hours
1 second = 1/3600 hours
1 second = 1/60 minutes
1 millisecond (ms) = 1/1000 seconds = 10-3 seconds
1 microsecond = 1/1000000 seconds = 10-6 seconds
1 nanosecond = 1/1000000000 seconds = 10-9 seconds

### Question 1

Convert 1 km / hr into inches / second.
Solution:
We first use the table of conversion of lengths to convert 1 km into inches
1 km = 39370.07 inches.
We next convert hours into seconds: 1 hour = 3600 seconds and we write
1 km/hr = 39370.07 inches / 3600 sec
= 10.9361 inches / sec

### Question 2

Convert 12.34 miles / hour into centimeters / minute.
Solution:
The table of conversion of lengths gives 1 mile = 160934.4 cm. Also 1 hour = 60 minutes. Hence
12.34 miles / hour = 12.34 × (160934.4 cm) / (60 mn)
= 3.30988 × 104 cm / mn

### Question 3

If someone is driving at 60 miles / hour, what is it in meters / second?
Solution:
The table of conversion of lengthsgives 1 mile = 1609.344 meters. Also 1 hour = 3600 seconds. Hence
60 miles / hour = 60 × 1609.344 m / 3600 sec
= 26.8223 m / sec

### Question 4

The speed of light is approximately 3 × 108 m / sec. What is the speed of light in km / hour?
Solution:
1 m = 0.001 km and 1 second = 1 / 3600 hour. Hence
3 × 108 m / sec = 0.001 × 3 × 108 / (1 / 3600)
= 1.08 × 109 km/hour

### Question 5

Convert 235 feet / seconds into meters / minute.
Solution:
1 foot = 0.3048 m and 1 second = (1/60) minutes. Hence
235 feet / seconds = 235 × 0.3048 / (1/60)
= 4297.68 meters / minute

More math problems with detailed solutions in this site.