Question

A particle can move only along $x-$axis. Three pairs of initial and final positions of particle at two successive times are given

Pair	Initial poistion	Final positioin
1	$-3m$	$+5m$
2	$-3m$	$-7m$
3	$+7m$	$-3m$

Find the sum of magnitudes of displacement in the pairs which give negative displacement in $m$.

Answer 1

Displacement in Pair 1 = $+5-(-3)=+8m$

Displacement in Pair 2 = $-7-(-3)=-4m$

Displacement in Pair 3 = $-3-(+7)=-10m$

Sum of magnitudes of displacement in the pairs which give negative displacement (pairs 2 and 3) = $4m+10m=14m$.