Question

How to calculate speed and velocity?

Answer 1

Hint: In this question, we will use the basic relation between speed, distance and time. Also, we will see the relation between velocity, position and time. We will also see the basic difference between speed and velocity for our better understanding.

Formula used:
$d = s \times t$
$v = \dfrac{{\Delta x}}{{\Delta t}}$

Complete answer:
As we know the relation between distance, speed and time is given by:
$d = s \times t$
$ \Rightarrow s = \dfrac{d}{t}$
Here, d is the distance covered by the object, t is the time taken by the object and s is the speed of the object.

Now, we will see the expression to find the velocity of an object:
$v = \dfrac{{\Delta x}}{{\Delta t}}$
Here, $\Delta x$ is the change in position, $\Delta t$ is the change in time and v is the velocity of the object or body.

Therefore, we get the two required expressions to find speed and velocity of an object.

Additional information:
We already know the basic difference between speed and velocity i.e., speed is given as the measure of how fast an object can travel, whereas velocity gives us the direction of this speed. Also, speed is a scalar quantity which means that it has only magnitude, whereas velocity is a vector quantity which means that it has both magnitude and direction. The S.I unit of both speed and velocity is meter per second (m/sec).

Note:
Here, it is important to remember most speedometers have a maximum limit up to 140-160 mph. We know that the S.I unit of speed is m/sec but the speedometer shows the value in km/h. Therefore, the question can be directly solved by having an idea of the unit of speed.