The odometer of a car reads 57321.0 km when the clock shows the time 08:30 AM. What is the distance moved by the car, if at 08:50 AM, the odometer reading has changed to 57336.0 km? Calculate the speed of the car in km/min during this time. Express the speed in km/h also.

The meter that measures the distance moved by a vehicle is known as an odometer.

Given,

Initial reading of odometer, ${\mathrm{d}}_1 = 57321.0 \mathrm{km}$

Final reading of odometer, ${\mathrm{d}}_2 = 57336.0 \mathrm{km}$

Initial time, ${\mathrm{t}}_1 = 8:30 \mathrm{AM}$

Final time, ${\mathrm{t}}_2 = 8:50 \mathrm{AM}$

a ) Total distance covered = Final reading of odometer - Initial reading of odometer

$\mathrm{d} = {\mathrm{d}}_2 -{\mathrm{d}}_1$

$\mathrm{d} = 57336.0 - 57321.0$

$\mathrm{d} = 15 \mathrm{km}$

b) Total time = Final time - Initial time

$\mathrm{t} = {\mathrm{t}}_2 -{\mathrm{t}}_1$

$\mathrm{t} = 08:50 -08:30$

$\mathrm{t} = 20 \mathrm{minutes}$

c) $\mathrm{Speed} \mathrm{of} \mathrm{the} \mathrm{car} (\mathrm{in} \mathrm{km}/\min ) = \frac{\mathrm{Total} \mathrm{distance}, \mathrm{d}}{\mathrm{Total} \mathrm{time}, \mathrm{t}}$

$\mathrm{s} = \frac{15}{20}$

$\mathrm{s} = 0.75 \mathrm{km}/\min$

d) $\mathrm{Speed} \mathrm{of} \mathrm{the} \mathrm{car}, \mathrm{s} (\mathrm{in} \mathrm{km}/\mathrm{h}) = ?$

$1 \mathrm{km}/\min = \frac{1 \mathrm{km}}{\left(\frac{1}{60}\mathrm{h}\right)} = 60 \mathrm{km}/\mathrm{h}$

$\mathrm{s} (\mathrm{in} \mathrm{km}/\mathrm{h}) = 60 \times 0.75 \mathrm{km}/\mathrm{h}$

$\mathrm{s} (\mathrm{in} \mathrm{km}/\mathrm{h}) =45 \mathrm{km}/\mathrm{h}$