Question

Two bodies, initially separated by x m and having an initial velocity 2 m $s^{-1}$ each, are moving towards each other along a straight line. If the rate of increase of their speeds is 3 m $s^{-2}$ and 2 m $s^{-2}$ respectively and the two meet after 4 seconds, find x.

• A. 12
• B. 40
• C. 56
• D. 66

Answer 1

The correct option is C 56

This is an example of the motion of a particle along a straight line moving with constant acceleration so we can use Kinematics equation of motion to solve the above problem

Let the two bodies be A and B with initial velocities $u_1$ and $u_2$ respectively and

$a_1$ and $a_2$ be the acceleration of the two bodies A and B respectively such that and

$x$ is the initial separation between A and B

$t$ be the time taken for A and B to meet so

let $x_1$ and $x_2$ be the distance covered by the bodies A and B respectively after time $t$ such that

using Kinematics equation of motion to find $x_1$ and $x_2$

Hence the initial separation between two bodies is 56 m