Question

The odometer of a car reads 68432 km when the clock shows the time 09.30 am. Find the distance covered
by the car, after reading in the odometer has changed to 68447 km at 10.00 am. Calculate the speed of the
car at this time duration.​

Answer 1

Answer:

30 km/h or 8.33 m/s

Explanation:

Type 1 :

Suppose that d = distance, v = speed, t = time

We know that d = vt

Therefore, v = d/t

             or, v = $\frac{15 km}{0.5h}$ [ d = 68447-68432 = 15 km, t = 30 min = 0.5 h]

             So,v = 30 km/h

Type 2 : (Unitary Method)

  In 0.5 hour the car covers 15 km

∴ In 1 hour the car covers ( 15/0.5) km      

                                         = 30 km

∴ The speed of the car is 30 km/h

km/h to m/s :

We know that 1 km = 1000 m

                       1 h = 3600 s

30 km/h = (30×1000) m/h

              = 30000 m/h

              = (30000÷3600) m/s

              ≈ 8.33 m/s