Question

It is $260$ km from Patna to Ranchi by air and $320$ km by road. An aeroplane takes $30$ minutes to go from Patna to Ranchi whereas a delux bus takes $8$ hours.
Find the average speed of the plane.

Answer 1

a) c) The average speed and average velocity will be same for plane.

${\overrightarrow{u}}_{avg}=u_{avg}=\frac{totaldistance}{totaltime}$

$=\frac{260km}{30min}$

$=\frac{260\times 1000m}{30\times 60s}=144.44m/s$

b) average speed of bus

$v=\frac{totaldistance}{totaltime}$

$=\frac{320\times 1000m}{8\times 60\times 60s}$

$=11.11m/s$

(d) for the average velocity of the bus

Total displacement by bus = total displacement by plane

$\therefore \underset{avg}{\overrightarrow{v}}=\frac{totaldisplacement}{totaltime}$

$=\frac{260\times 1000m}{8\times 60\times 60s}$

$=9.03m/s$