question_answer

The three initial and final position of a man on the x-axis are given as:

(i) (-8m, 7m),

(ii) (7m, - 3m) and

(iii) (-7m, 3m)

Which pair gives the negative displacement?

A) (i)                                

B) (ii)

C) (iii)                               

D) (i) and (ii)

Correct Answer: B

Solution :

  The displacement of the man from A to E is \[\Delta x={{x}_{2}}-{{x}_{1}}=7m-\left( -8m \right)=+15\text{ }m\] directed in the positive x-direction. (ii) The displacement of the man from E to C is \[\Delta x=-\,3\,m-\left( 7m \right)=-10\text{ }m\] directed in the negative x-direction. (iii) The displacement of the man from B to D is \[\Delta x=3m-\left( -7m \right)=+10\text{ }m\] directed in the positive x-axis.