Question

A man leaves his house for a cycle ride. He comes back to his house after half an hour after covering a distance of 1km. What is the average velocity for the ride?
A. 0 km/h
B. 2 km/h
C. 10 km/h
D. 0.5 km/h

Answer 1

Hint: Average velocity is defined as the rate at which an object changes its position from one place to another. To find the required solution of the given question we will first find the displacement of the man then apply the formula of average velocity for the correct answer.
Formula Used:
Average velocity $ = \dfrac{{{\text{Total displacement}}}}{{{\text{Time}}}}$
$ \Rightarrow v = \dfrac{x}{t}$

Complete answer:
An object which is moving with variable velocity, for that average velocity is defined as the ratio of its total displacement to the total time interval in which that displacement occurs.
Mathematically, it can be given as,
$v = \dfrac{x}{t}$
Where v is the average velocity, x is the displacement and t is the time.
It is given in the question, that the man returned to his house after the ride. Since, he returned to the same place, so displacement will be zero for the man as final and initial position are the same.
Average velocity of his ride $ = \dfrac{{displacement}}{t} = \dfrac{0}{{\dfrac{1}{2}}} = 0$
In physics, velocity means displacement over a particular time interval, here the man has again come to the same position therefore, the average velocity for the ride is zero km/h.

Hence, option (A) is the correct answer.

Note:
In questions like these students need to remember that velocity is not affected by the distance but by the displacement. Average velocity of an object moving with a variable speed is given by the ratio of the displacement and time. A body is said to be moving with variable velocity if either its speed changes or direction of motion changes or both change with time.