Question

A car covers the half of the distance between two places at the speed of 40 km/hr and second half of 60km/hr . What is the average speed of the car

Answer 1

Answer:

Average speed = 24 km/h

Step by step explanations :

Given that,

A car covers the half of the distance between two place

at the speed of 40 km/hr

and second half of 60 km/hr

Let the total distance travelled by the car be d

Time taken to cover d/2 km

at speed 40 km/h

= d/40 hr

Time taken to cover d/2 km

at speed 60 km/h

= d/60 hr

Average speed

=total distance travelled/total time taken

Total distance covered = d

Total time taken = d/40 + d/60

= (3d + 2d) /120

= 5d/120

= d/24

so,

Average speed = d/(d/24)

= 24d/d

= 24 km/h

so,

Average speed = 24 km/h

Answer 2

$\bold {\huge {Your ~answer :-}}$

$\bf\huge\boxed{24\:km/h}$

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Explanation —

Given-

v1 = 40 km/h

v2 = 60 km/h

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We know that

Average speed<v>

$\huge v = \frac{distance}{total\:time}$

Now,

Let s be the total distance

So,

$= > v = \frac{s}{t}$

Simce t can be written as

s = vt => t = s/v

$= > v = \frac{s}{ \frac{s1}{v1} + \frac{s2}{v2} }$

Now putting

Since half of the distance therefore we can write s------> s/2

$= > v = \frac{s}{ \frac{ \frac{s}{2} }{40} + \frac{ \frac{s}{2} }{60} }$

On solving we got

=> v = 24

Therefore average speed of the car is 24 km/h

$\huge{\red{\ddot{\smile}}}$