question_answer

A person moves \[30\text{ }m\]north and then \[20\text{ }m\] towards east and finally 30^2 min south-west direction. The displacement of the person from the origin will be

A)  \[10\text{ }m\]along north

B)  \[10\text{ }m\]along south

C)  \[10\text{ }m\] along west

D)  zero

Correct Answer: C

Solution :

Taking the starting point as O, we have \[30\text{ }m\] north OA, \[20\text{ }m\]east AB, and finally \[30\sqrt{2}m\] \[(S-E)\] BD. From  \[\Delta CAB,\] \[AC=20m,\text{ }OC=10m\] In \[\Delta OCD,\] \[OD=OC,\text{ }OD=10m\] Hence, final displacement from origin is 10 m.