Question

7. A train travels with a speed of 60 km h-1 from
station A to station B and then comes back with
speed 80 km h- from station B to station A. Find.
(i) the average speed, and (ii) the average velocity
of train.
Ans. (i) 68.57 km h-1, (ii) zero​

Answer 1

Explanation:

average velocity can be found by this method but you have not mentioned the time in the ques. so please tell the time for average speed. Formula is

average speed =total distance÷total time

Answer 2

$\mathfrak{\huge{\red{\underline{\underline{AnswEr :}}}}}$

» Average Speed = 68.57 km/hr

» Average Velocity = 0

$\mathfrak{\huge{\red{\underline{\underline{ExplanaTion :}}}}}$

Given :

A train travels with a Speed of 60 km/hr from Station A to Station B and with a Speed of 80km/hr from Station B to Station A.

Let

⚘ Distance = Constant

⚘ Speed1 (x) = 60km/hr

⚘ Speed2 (y) = 80km/hr

Find :

1. The Average Speed of Train

2. The Average Velocity of Train

Solution :

1] When the Distance is Constant then the Average Speed is Equivalent to Twice of Product of Speed1 and Speed 2 Upon Sum of Speed1 and Speed 2

$\huge\boxed{ A.S. = \frac{2xy}{x + y} }$

$\large {A.S. = \frac{2 \times 60 \times 80}{60 + 80}}$

$\large {A.S. = \frac{2 \times 60 \times 80}{140}}$

$\large {A.S. = \frac{480}{7}}$

$\large {A.S. = 68.57 \: km/hr}$

$\mathscr\pink{Average\:Speed\:=\:68.57\:km/hr}</p><p>$

2] Average Velocity is equivalent to Rate of Displacement.

$\huge \boxed{A.V. = \frac{Displacement}{Time} }$

$\large{A.V. = \frac{0}{t}}$

» As Displacement is Zero Here Because Train Traveled Back to its Initial Point.

$A.V. = 0$

$\mathscr\pink{Average\:Velocity \:=\:Zero(0)}</p><p>$