1. What is Speed?
Distance: It is a measure of how far an object moves.
Speed is a measure of the distance an object travels in a certain time. It can simply be calculated as distance over time. Speed tells us how fast or slow something is moving. Meters per second, kilometers per hour, etc. are the different units used to measure speed.
1.1 How to find Speed?
Formula to calculate Speed when Distance and Time are known.
Example: A car travels a distance of 600 km in 12 hours. What is its speed in km/hr?
Solution:
Distance traveled by car = 600 km
Time taken by the car = 12 hours
Using the formula:
Speed=Distance ⁄ Time
Speed = 600⁄12=50 km/hr.
Speed of the car is 50 km/hr.
1.2 How to find the Distance?
Formula to calculate Distance when Speed and Time are known.
Example: A cyclist travels at 14 km/hr. for 5 hours. What is the total distance traveled by the cyclist?
Solution:
Speed of the cyclist = 14 km/hr.
Time taken = 5 hours
Using the formula:
Distance = Speed × Time
Distance = 14 × 5 = 70 km
Distance traveled by the cyclist = 70 km
1.3 How to find the time?
Formula to calculate Time when Speed and Distance are known.
Example: A swimmer swims at a speed of 2.5 m/s in still water. What will be the time taken by this swimmer to swim 750 meters?
Solution:
Distance = 750 m
Speed of the swimmer = 2.5 m/s
Using the formula:
Time = Distance ⁄Speed
Time =750/2.5 = 300 seconds
Swimmer will take 300 seconds to swim 750 meters.
2. Easy way to remember formulas
You can use the triangle shown below and get the formulas to find either speed, distance or time.
In order to use this triangle to get the formula, cover the value you need to find and you will see the formula with the location of the remaining two values you can see.
For example, if you need to find the distance, cover the distance section in the triangle, you will get the formula as : Distance = Speed × Time.
If you need to find time, cover the time section in the triangle, you will get the formula as
Time = Distance ⁄Speed.
