Question

A body rising vertically up to a height of 125 m in 5 s and then comes back at the point of projection. Find the displacement.
A) $25m$.
B) $250m$.
C) $125m$.
D) $0m$.

Answer 1

Hint:It is given that the body goes upwards and then returns to the initial position of projection along vertical direction, if we will find out the displacement along the vertical direction we can find the correct answer to this problem. We do not need to apply the equation for Newton's law of motion, just the calculation of displacement along the vertical direction, enough to find the value of the answer to this problem.

Step by step solution:
Step 1.
While it is given that the body is rising as it is given as $s = 125m$, $t = 5s$ and $a = - g$.
Displacement of a body is known as the shortest distance travelled between the points. As we know that the body moves upwards and finally it reaches to the initial point which means that the vertical displacement is zero meters. Displacement of the body is zero.
So the correct answer is option D i.e. $0m$.

Note:The value of shortest distance between two points is known as displacement. The displacement is the shortest distance between any two points which means displacement has magnitude as well as direction as we need to find the direction in which we will get the shortest distance. Therefore displacement is a vector quantity. Students should also remember that displacement is a vector quantity as sometimes it is directly asked in multiple choice questions (MCQs).