Suppose a person travels distance of 6 kilometers in 2 hours
What is his speed
His Speed is 3 Kilometers per hour
What is Speed
It is distance travelled per unit of time
How to Calculate Speed
Speed = Distance/Time
How is it measured
It is normally measured in kilometer per hour
Shorter Distances are also measured in meter per seconds
Example 1
Suppose an aeroplane travels distance of 1600 kilometers in 2 Hours
What is speed of Plane
Distance = 1600 km
Time = 2 hours
Speed = Distance/Time
= 1600/2
= 800 Km/Hour
Example 2
Suppose an athlete runs 200 meter race in 25 seconds
What is his speed in meter per second?
Distance = 200 m
Time = 25 Seconds
Speed = Distance/Time
Speed = 200 /25 = 8 meter per second
Note
1 Km = 1000 meters
I Meter = 100 centimeters
I hour = 60 Minutes
1 Minutes = 60 Seconds
Now, lets find speed in different units
Questions
Q 3 Page 102 - What does the odometer of an automobile measure?
Q 5 Page 102 - A driver of a car travelling at 52 km h–1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h–1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?
