Question

Name a device that measures distance travelled in automobiles. A body travels a distance of 15m fro A to B and then moves a distance of 20 m at right angle to AB. Calculate the total distance travelled and the displacement.

Answer 1

• The device measuring distance travelled in automobiles is Odometer.

$$\begin{gathered} \mathrm{Distance}\mathrm{travelled}: \\ \mathrm{d}=\mathrm{Total}\mathrm{length}\mathrm{of}\mathrm{the}\mathrm{path}\mathrm{in}\mathrm{which}\mathrm{the}\mathrm{body}\mathrm{actually}\mathrm{travelled} \\ =15+20 \\ =35\mathrm{m} \\ \mathrm{Displacement}: \\ \mathrm{d}=\mathrm{Shortest}\mathrm{distance}\mathrm{between}\mathrm{starting}\mathrm{and}\mathrm{ending}\mathrm{points} \\ =\sqrt{{15}^2+{20}^2} \\ =\sqrt{225+400} \\ =25\mathrm{m} \end{gathered}$$