Question

A person covered the first 40 km of his journey at 50 km/hr, the next 70 km at 35 km/hr and the remaining distance in 2 minutes. If the average speed for the entire journey is 52 km/hr, then find the distance covered in the last stretch of the journey.

Answer 1

Answer:

The distance covered in the last stretch of journey is 2.367km

Step-by-step explanation:

Here,

Velocity for first 40km, V1= 50km/h

Velocity for second 70km, V2= 35km/h

Velocity for last Skm, V3=?

We know,

Average velocity=(V1+V2+V3)/3

Average velocity=(V1+V2+V3)/3or, 52=(50+35+V3)/3

Average velocity=(V1+V2+V3)/3or, 52=(50+35+V3)/3or, 156=85+V3

Average velocity=(V1+V2+V3)/3or, 52=(50+35+V3)/3or, 156=85+V3or, V3= 71

The person travelled at 71km/h or, 1.183km/m for the last 2 minutes.

So, Distance travelled, S=V3× Time travelled

Distance travelled, S=V3× Time travelled= 1.183×2

Distance travelled, S=V3× Time travelled= 1.183×2= 2.367km

The distance covered in the last stretch of journey is 2.367km