Example 3.1 A car is moving along a
straight line, say OP in Fig. 3.1. It moves
from 0 to P in 18s and returns from P to
in 6.0 s. What are the average velocity
and average speed of the car in going (a)
from O to P ? and (b) from 0 to P and back
to Q?
Answers
Answer:
Correct option is A)
$$(a)$$
Displacement from O to P=360m
Time taken from O to P=18sec
Velocity of car =
Time
Displacement
=
18
360m
Avg. Velocity of car (O to P)=20ms
−1
Time taken from P to Q=6sec
Total time taken to move from O to P and back at Q,
T
′
=16+6=24
Displacement from P to Q=240m
Average speed of car from P to Q=
24sec
240m
=10ms
−1
Time taken from O to P=18sec
Velocity of car =
Time
Displacement
=
18
360m
Avg. Velocity of car (O to P)=20ms
−1
Time taken from P to Q=6sec
Total time taken to move from O to P and back at Q,
T
′
=16+6=24
Displacement from P to Q=240m
Average speed of car from P to Q=
24sec
240m
=10ms
−1