Question

Rachel rides her bike east for 3.0 miles. She then turns around and rides west for 4.8 miles. What is her displacement?

Answer 1

$\underset{A}{\rightarrow}$ = displacement of the bike in east direction = 3 miles

$\underset{B}{\rightarrow}$ = displacement of bike in west direction = - 4.8 miles

net displacement of the motion of the bikes can be given as

\underset{R}{\rightarrow} = $\underset{A}{\rightarrow}$ + $\underset{B}{\rightarrow}$

inserting the above values

\underset{R}{\rightarrow} = 3 + (- 4.8)

\underset{R}{\rightarrow} = - 1.8 miles

hence the net displacement is 1.8 miles in west direction since the negative sign indicates west direction.