Question

a boy leaves his house at 9:30 a.m. for the school the school is 2 kilometre away and the classes starts at 10:00 a.m. if he walks at the speed of 3 kilometre per hour for the first kilometre at what speed should he walk second kilometre to reach just in time​

Answer 1

Answer:

He should walk the second kilometre in speed = 6km/hr to reach just in time.

Explanation:

The total distance = 2 kilometer

Speed of the boy for the first kilometer

= 3 km/hr

Hence the time taken by him to cover the first kilometer distance .:

t = distance / speed

=> t = (1/3) hr = 60/3 = 20 minutes

Thus the time left to cover the remaining one kilometer = total time available - time already consumed

=> time left in minutes = 30 - 20= 10

Hence the speed required to reach school at time = 1km/10min....(eq.1)

= 1000m/10min = 100meter/minute

In meter per second

= 100/60 = 10/6 = 1.67 m/s

In kilometer per hour

speed = 1km/10min (from eq.1)

= 1÷1/6 km/hr

which equals to 1×6/1 = 6km/hr