Question

An aeroplane flies $400m$ north and $300m$ south and then flies $1200m$ upwards, then net displacement is:

• A. 1200 m
• B. 1300 m
• C. 1400 m
• D. 1500 m

Answer 1

Answer: (B)

An aeroplane flies $400m$ north and $300m$ south so let aeroplane starts there journey from point $O$

Net displacement of the plane is $100m,$ after it flies $1200m$ upward; so the displacement or position is
$\overrightarrow{\mathrm{r}}=100\hat{\mathrm{i}}+1200\hat{\mathrm{j}}$ Magnitude of displacement $=\mathrm{r}=\sqrt{(100{)}^2+(1200{)}^2}$ $\mathrm{r}=\sqrt{10000+1440000}$ $=1204\mathrm{m}$