Question

likes dedo koi TT
Example 4 A car travelled the first half of its journey at 40 km/h and the next half at 60 km/h. Find the average speed of the car over the whole journey.​

Answer 1

$\large\sf\star{\underline{\underline{\color{cyan}{Answer}}}}$

$\footnotesize \text{Let \: x \: consider, \: x \: = \: total \: distance \: covered \: by \: the \: car,}$

$\footnotesize \text{Time \: taken \: to \: complete \: the \: half \: distance \: with \: velocity \: v \: = \: 40km/h,}$

$\footnotesize \text t_{1} = \frac{x}{2 \times 40} = \frac{x}{80} hr....(1)$

$\footnotesize \text {The \: time \: taken \: to \: complete \: another \: half \: distance \: with \: velocity \: u \: = \: 60km/h}$

$\footnotesize \text t_{2} = \frac{x}{2 \times 60} = \frac{x}{120} hr$

$\footnotesize \text{The \: total \: time \: taken, }$

$t = t_{1} + t_{2}$

$t = \frac{x}{80} + \frac{x}{120} = \frac{x}{48} hr$

$\footnotesize \text{The average speed of the car, }$

$\large\sf\star{\underline{\underline{\color{pink}{v_{avg} = \frac{x}{x/48} = 48km/h}}}}$

─━━━━━━━━━━━━━━━━━━━━━━━─

Pls Mark As Brainliest bhaiya :)

Answer 2

Answer :

• Time taken to complete the half distance with velocity v = 40km/h,

$\sf \text t_{1} = \frac{x}{2 \times 40} = \frac{x}{80}$

$\pink{\text {\underline {The \: time \: taken \: to \: complete \: another \: half \: distance \: with \: velocity \: u \: = \: 60km/h}}}$

$\sf\text t_{2} = \frac{x}{2 \times 60} = \frac{x}{120}$

$\bf \text{The \: total \: time \: taken, }$

$\bf \: t = \frac{x}{80} + \frac{x}{120} = \frac{x}{48}$

$\purple{\text{The average speed of the car : }}$

$\large\bf \{\underline{\underline{\color{red}{{avg} = \frac{x}{x/48} = 48km/h}}}$