Question

The odometer of a car reads 2000 km at the start of a trip and 2400 km at the end of the trip. If the trip take took 8 h, calculate the average speed of the car in km/h and m/s.

Answer 1

Given :

Initial odometer reading=2000km
Final odometer reading=2400km
Total distance= Final distance- Initial distance
=2400-200=400km
Total time=8h
Average speed =?

Formula to be used :
Average speed= Total Distance/Total time

Average speed in Km/hr:
Average speed=400/8
=50 km/hr

Average Speed in m/s:
1km/hr=5/18 m/s
∴50km/hr=50x5/18=250/18=13.88m/s

Answer 2

distance covered by the car,
s= 2400km - 2000km = 400km,
time elapsed, r = 8h,
average speed of car is,
average velocity = s/t , 400km/8h,
= 50 km h/s
= 50 km/h X 1000m/1km X 1h/3600s
= 13.9m/s