Question

A particle travel 1st half distance with uniform speed of 40m/s and next half distance with uniform speed of 80m/s calculate average speed.​

Answer 1

Solution -

Given :

A particle travels it's 1st half of the distance with a speed of 40 m/s and next half distance with speed of 80 m / s . The speed was uniform

To find :

The average speed of the particle

Answer :

Let the speed of first half distance be $speed_1$ and speed for the second half distance be $speed_2$ .

Now , According to the given Question we have

$\sf\implies\: Average\:speed\:=\:\dfrac{speed_1\:+\:speed_2}{2}$

$\sf\implies\: Average\:speed\:=\:\dfrac{40\:+\:80}{2}$

$\sf\implies\: Average\:speed\:=\:\dfrac{120}{2}$

$\bf\boxed{\implies\: Average\:speed\:=\:60\:m/s}$

So the calculated average speed of the particle is 60 m/s .

Suppose if the time taken by particle to cover the first half and other half of the distance would be given . Will the answer be same ??

Answer : No in such a case we would use the formula

$\bf\boxed{\implies\: Average\:speed\:=\:\dfrac{speed_1\:+\:speed_2}{time_1\:+\: time_2}}$

As the average speed of a body is total distance covered upon total time taken

Answer 2

Given:-

• A particle travel 1st half distance with uniform speed of 40m/s.
• half distance with uniform speed of 80m/s.

To find:-

• Average speed of particle.

Answer:-

Average speed = $\sf{\dfrac{Speed 1 + Speed 2}{2}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= $\sf{\dfrac{40 +}{80}{2}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= $\sf{\dfrac{120}{2}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= $\boxed{60 m/s}$

•°• Average speed of particle is 60 m/s.