Question

A car travels from station A to station B at 30kmph during its return trip to A
travels at 30kmph for first half distance and at 70kmph for next half distane,
Find the average speed of the car. Find also its average velocity.​

Answer 1

Explanation:

avg speed from B to A =(2V1 V2)/V1 +V2

if equal distances are covered in two intervals

= (2×30×70)÷30+70

=4200÷100

=42

Avg speed = (30+42)÷2

=36

Avg velocity=0 ,( as displacement=0)

Answer 2

Answer:Average Velocity = 0;Average Speed = 35kmph

Explanation:

Let distance between A to B is x

Average Velocity = 0 because displacement = 0

average speed is total distance/total time

THEN

Total distance = 2x and Total time=distance / speed

Lets first find average speed of speeds during return trip to A that is

$x/(2/70)+(x/2/30)$ after simplification 5x/210.Now lets go to main equation.

$2x/(x/30+5x/210)$after simplification answer is 35kmph