Question

A bus moves at auniform speed v1 for some time and then with a uniform speed v2.

Answer 1

Answer:

Given :

Distance - Time graph:

Time (min) 0 20 40 60 80 100 120

Distance(Km) 0 20 40 65 95 125 155

1. Find the values of v1 and v2:

V1=Distance/Time=20/20=1km/min

V2=1.25km/hr

2.When did the bus change it's speed?

Bus changed its speed when t=60min

3.What is the distance covered in the 1st hour?

Distance covered in first hour is 65km

4.What is the distance covered in the 2nd hour?

Distance covered in second hour is 155-65km=90km

5.What is the average speed for the complete journey?

Average speed=total distance/total time

total distance=155km

time=120min =2hours

Average speed=155/2=77.5km/h