Speed and Distance

Speed tells you how fast something is moving. Distance tells you how far it goes. Time tells you how long it takes. These three ideas are connected by a simple formula: distance equals speed times time.

The Formula

The formula is easy to remember: Distance = Speed x Time. If a car drives at 60 miles per hour for 2 hours, it travels 120 miles. You just multiply the speed by the time.

You can rearrange the formula too. Speed = Distance / Time. If you run 1 mile in 10 minutes, your speed is 0.1 miles per minute, or 6 miles per hour.

Speed in Real Life

Speed is measured in different units. Cars use miles per hour. Planes use miles per hour or knots. Wind is measured in miles per hour too. Scientists often use meters per second.

Knowing about speed helps you plan trips. If your destination is 150 miles away and you drive 50 miles per hour, it will take 3 hours. That is distance divided by speed.

Fun Facts

• The fastest animal on land is the cheetah, which can run about 70 miles per hour.
• The speed of sound is about 767 miles per hour.
• Light travels at about 186,000 miles per second, the fastest speed possible.

Did You Know?

A snail moves at about 0.03 miles per hour. At that speed, it would take a snail more than 3 days to travel just 1 mile!