A motorcycle covers 50 km at a speed of 25 km/h. Find the speed of the motorcycle for the next 50 km of the journey so that the average speed of the whole journey will be 30 km/h.
Answer & explanation
Correct answer: option 2
As distance is same .
So ,
Average Speed = \(\frac{2 × S1 × S2 }{S1 + S2}\)
30 = \(\frac{2 × 25 × S2 }{25 + S2}\)
30 = \(\frac{50 × S2 }{25 + S2}\)
750 + 30 S2 = 50 S2
20 S2 = 750
S2 = 37.5 km/h
So , Speed of motorcycle is 37.5 km/h