Question

(6) Two cars start from the same spot at the same time in the same direction. The first car goes
at a uniform speed of 10km/h and the second car starts at a speed of 8 km/h, later increasing
the speed by half km/h every succeeding hour, Aller how many hours will the second car
overtake the first car​

Answer 1

Answer:

second car will overtake 1st car after 9 hours

Step-by-step explanation:

Speed of second car is in the form of an A.P, with speed increasing as 1/2 km/h

8 , 8.5 , 9 , 9.5, 10 , 10.5 , 11, 11.5, 12

The first car moves at a constant rate of 10 km/hr

1st hour: 2nd car covers 2 kms less than 1st

2nd hour: covers 1.5 kms less

3rd hour: covers 1 km less

4th hour: covers 0.5 km less

5th hour: speed of both car same

Hence till 5 hours, second car is behind 1st car by: 2+1.5+1+0.5 = 5 km

6th hour: second car covers 0.5 km more than 1st

7th hour: 1 km more than 1st

8th hour: 1.5 km more than 1st

9th hour: 2 km more than 1st

Thus now the distance covered by both cars become equal.

Hence second car will overtake 1st car after 9 hours

Hope it helps.