Question

4- A car travels 100 km and a speed of 60 km 1h and returns
with a speed of 40 kmth. Calculate its average speed
and average velocity.​

Answer 1

Answer:

Average speed = Total distance / Total time

=> 100+100 / t1 +t2

We know that time = d/s

=> t1 = 100/60 = 5/3

=> t2 = 100/40 = 5/2

Average speed = 200 / 5/2+5/3

=> 200 / (15+10)/6

=> 200 / 25/6

=> 200×6 / 25

=> 1200 / 25

=> 48 km/h

Average speed for whole journey = 48 km/h

Answer 2

Answer :-

⏩Given :-

▪️Speed for traveling 100 km = 60 km/h

▪️Speed for returning 100 km = 40 km/h

◾Now to find out avg. velocity and avg. speed we must find out time taken .

◾As time taken

$\sf{ t = \dfrac{distance}{speed}}$

◾Then

$\sf{t_1 = \dfrac{100}{60} }$

$\sf{t_1 = \dfrac{5}{3} }$

$\sf{t_2 = \dfrac{100}{40} }$

$\sf{t_2 = \dfrac{5}{2} }$

◾Now :-

⏩Avg. Speed

$= \dfrac{Total\: distance}{Total\: time}$

$= \dfrac{2d}{t_1 + t_2}$

$= \dfrac{200}{\dfrac{5}{3} + \dfrac{5}{2}}$

$= \dfrac{200}{\dfrac{10+15}{6}}$

$= \dfrac{200\times6}{25}$

$= 8 \times 6$

$\bold{= 48 \: km/h}$

⏩Avg. Velocity

▪️As displacement = 0

▪️As displacement = 0

▪️Hence the Avg. velocity = 0