Question

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.

Answer 1

Step 1: Given data

Initial reading of odometer = $\text{57321.0 km}$

Final reading of odometer = $\text{57336.0 km}$

Initial Time = $\text{8:30 AM}$

Final Time =$\text{8:50 AM}$

Step 2: Calculation of the distance moved by car:

Total distance covered = Final reading of odometer - Initial reading of odometer
= $\text{57336.0km - 57321.0}km$

= $15km$

Step 3: Calculation of the time taken by the car:

Total time taken= Final Time - Initial Time

= $\text{8:50 AM - 8:30 AM}$

= $\text{20 minutes}$
= $20\times \frac{1}{60}hr=\frac{1}{3}hr$

Step 4: Calculation of the speed of the car in $kmmi{n}^{-1}$ :

We have

Speed= $\frac{Distance}{time}$

Thus,

The speed of the car will be;

$=\frac{15km}{20min}$

$=\frac{3}{4}$

$=0.75kmmi{n}^{-1}$

Step 5: Calculation of the speed of the car in $km{h}^{-1}$ :

$1kmmi{n}^{-1}=\frac{1km}{1min}$

$=\frac{1km}{\frac{1}{60}hr}$

$=60km{h}^{-1}$

Thus,

$0.75kmmi{n}^{-1}=60\times 0.75km{h}^{-1}$

$=45km{h}^{-1}$

Thus,

Total distance covered by the car= $15km$

Total time taken by the car = $20minor\frac{1}{3}hr$

Speed of the car in $kmmi{n}^{-1}$ = $0.75kmmi{n}^{-1}$

Speed of the car in $km{h}^{-1}$ = $45km{h}^{-1}$