A man walks 7 km in 2 hours and 2 km in 1 hour in the same direction

a) What is man's average speed for the whole journey?

b) What is man's average velocity for the whole journey?

The average speed of a body in a certain time interval is the distance covered by the body in that time interval divided by time.

Average velocity is defined as the displacement by the total time taken.

Answer: For a man walking 7 km in 2 hours and 2 km in 1 hour in the same direction the

a) Average Speed = 3 km/h     b) Average Velocity = 3 km/h

Speed is defined as the rate at which an object is moving (covering a particular distance). It is a scalar quantity as it defines only the magnitude and not direction whereas, velocity is a vector quantity. It depends upon both magnitude and direction.

Explanation:

a) Average speed of the man is calculated by dividing the total distance covered by the man by the total time taken by him.

Average Speed = ( total distance covered) / ( total time taken)

= (7 + 2) / ( 2 + 1)

= 9/3

= 3 km/h

b) Average velocity of the man is calculated by dividing the total distance covered by the man in one direction by the total time taken by him.

Since both the distance traveled by the man is in the same direction, therefore, total displacement is the same as total distance covered by him.

Average Velocity = ( total displacement) / ( total time taken)

= (7 + 2) / ( 2 + 1)

= 9/3

= 3 km/h

Therefore, a) Average Speed = 3 km/h     b) Average Velocity = 3 km/h