A car is traveling at a speed of 90 kilometers per hour. What's the car's speed in meters per second? How many meters will the car travel in 10 seconds? Do not round your answers.

It's 25 meters per second, and it travels 250 meters in ten seconds.

To convert kilometers per hour to meters per second, you start with turning that into a fraction, 90km/1hr. To convert to meters, you have to multiply that fraction by another fraction with km as a label on the denominator, and m (meters) as a label for the numerator. That fraction would be 1,000m/1km, because there are 1,000 meters in 1 kilometer. You would also add another fraction to the multiplication sentence to convert hours to seconds. There are 3,600 seconds in 1 hour, so that fraction would be 1hr/3,600sec, and then cross out all km and hr labels. After that, you could cross reduce two of the zeros in 3,600 and 1,000 because they are diagonal to each other, and this also makes simplifying way easier. You are left with this: 90/1 times 10m/1 times 1/36sec. Multiply straight across and you would get 900 meters/36 seconds. Divide both sides by 36, and you are left with 25 meters/1 second. The car travels 25 meters per second. Now we have to find how many meters the car travels in 10 seconds. This step is very simple: just multiply 25 meters by 10 and 1 second by 10 to get the number of meters. 25 times 10 = 250, so the car travels 1 meter per second and 250 meters in 10 seconds.