Question

A motorcyclist covers 1/3 of a given distance with a speed of 10 kmhâ»Â¹, the next 1/3 at 20 kmhâ»Â¹ and the last 1/3 at of 30 kmhâ»Â¹. What is the average speed of the motorcycle for the entire journey?

Answer 1

Answer: 180/11 km/hr

Explanation:

3/Vavg =1/10+1/20+1/30

3/Vavg =6+3+2/60

Vavg=60*3/11

Answer 2

Answer:

average velocity of the motorcycle will be 16.36 m/s.

Explanation:

Let's consider the total distance be x

Then,

According to question,

time taken to cover 1/3 of total distance,

$t_1\ =\ \dfrac{distance}{speed}$

      $=\ \dfrac{x}{3\times 10}$

   $=\ \dfrac{x}{30}$

$t_2\ =\ \dfrac{distance}{speed}$

      $=\ \dfrac{x}{3\times 20}$

      $=\ \dfrac{x}{60}$

$t_2\ =\ \dfrac{distance}{speed}$

     $=\ \dfrac{x}{3\times 30}$

      $=\ \dfrac{x}{90}$

$average\ speed\ =\ \dfrac{total\ distance}{total\ time}$

                            $=\ \dfrac{x}{\dfrac{x}{30}+\dfrac{x}{60}+\dfrac{x}{90}}$

                           $=\ \dfrac{x}{\dfrac{11x}{180}}$

                            $=\ \dfrac{180}{11}$

                            = 16.36 m/s

So, the average velocity of the motorcycle will be 16.36 m/s.