Question

How far will the jeep travel in $2{\text{h}}$ at $20{\text{m}}{{\text{s}}^{ - 1}}$ ?

Answer 1

Hint: When a body moves from one point to another, we call that displacement and the rate of change of displacement with respect to time is known as velocity. In the given question we are given the time of the displacement and the velocity of the jeep and we need to find the distance travelled.
Formula used:
$v = \dfrac{{s}}{{ t}}$, where $ s$ is change in displacement and $ t$ is change in time.

Complete step by step solution:
When a body covers the distance in some given time interval then the speed of the body is given as
$v = \dfrac{{ s}}{{ t}}$
For finding the distance travelled by the jeep we should know the time interval for which we need to calculate the distance covered and the velocity of the jeep. We are given the values of speed and time. We need to convert the time and the speed to the S.I unit before solving.
Therefore we have,
The given interval $t = 2{\text{h = 2}} \times {\text{60}} \times {\text{60 = 7200sec}}$
We converted the units of the time given to seconds.
The given speed $v = 20{\text{m}}{{\text{s}}^{ - 1}}$
So the distance travelled will be
$ s = v \times t$
Substituting the values in the above equation we have
$ \Rightarrow s = 20 \times 7200 = 144000{\text{m = 144km}}$
We converted the distance from metres to kilometres.
Hence the distance travelled by the jeep with a speed of $20{\text{m}}{{\text{s}}^{ - 1}}$ in $2{\text{h}}$ is $144{\text{km}}$.

Note: Note that we need to convert the units of the time given before calculating the value of the distance into the MKS system. Distance is the path followed by the vehicle in the given time and displacement is the shortest distance travelled by the vehicle in the given time interval. Distance is a scalar quantity whereas displacement is a vector quantity.