Question

III

MODULE 2. NUMBERS AND QUANTITIES
Converting between compound units: Advanced
A car is traveling at a rate of 35 meters per second. What is the car's rate in kilometers per hour? How many kilometers will the car travel in 5 hours?
round your answers.

Answer 1

120km/h

600km in 5 hours.

Explanation:

1000 meters is equal to 1 kilometer. 1 meter is equal to .001 kilometer.

You can set up an equation like this to solve for the car's rate in kilometers.

`(1 km)/(1000 m) = (x km)/(35m)` or
`(1000 m)/(1000 km) = (x m)/(35km)`.

Now crossmultiply either fraction to solve for x.

`(1 km)/(1000 m) = (x km)/(35m)\\(1 km)/(1000 m)*35 = (x km)/(35m)*35\\(35 km)/(1000 m) = xkm`

The car is going at .035km/sec. Now we need to multiply this to get kilometers per hour. There are 60 seconds in a minute and there are 60 minutes in a hour.

`(35)/(1000) * 60 * 60`

The car travels at 120km per hour.

Since we now know the rate in kilometers per hour. We can multiply the rate by 5 since the question asks how many kilometers the car will travel in 5 hours.

120 * 5 = 600

The car will travel 600km in 5 hours.