Question

A bus moves at a uniform speed v1 for some time and then with a uniform speed of v2. The distance time table is given below. Plot 5 he distance time graph and answer the following questions. Time ( min ) distance ( km ) 0 0 20 20 40 40 60 65 80 95 100 125 120 155 Ques : 1. Find the values of v1 and v2? 2. When did the bus change it's speed? 3. What is the distance covered in the 1st hour? 4. What is the distance covered in the 2nd hour? 5. What is the average speed for the complete journey?

Answer 1

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

Answer 2

Answer:

a.) nhi aata

b.) bus change its speed when t=50 min

c.) distance covered in first hour is 65 km.

d.) distance covered in second hour is 155-65=90 km

e.)avg speed=d/t=155km/120min=2hours

155/2=77.5km/h