CBSE BOARD XII, asked by chinnu7957, 1 month ago

A car travels x km at 60 km/hour

Answers

Answered by MuskanJoshi14
0

Explanation:

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Given:

A car travels x km at 60km per hr and then travels another 2x km at 40km/hr.

To find:

The average speed for the entire distance.

Solution:

As we know that when an object is moving at a speed 's' and covers distance 'd' in time 't' then its speed is given by:

s =  \frac{d}{t}

So,

As given,

The speed of the car when it travels x km = 60 Km/hr.

So, the time that is taken by the car to travel x km

  = \frac{x}{60} hr

Also,

the speed of the car when it travels 2x km = 40 Km/hr.

So, the time that is taken by the car to travel 2x km.

 =  \frac{20}{40} km

  = \frac{x}{20} km

Hence,

the average speed for the entire distance.

  = \frac{total \: distance \: travelled}{total \: time \: taken}

 =  \frac{x + 20}{ \frac{x}{60}  + \frac{x}{20}  }

On solving the above, we get

 =  \frac{3}{ \frac{x + 3x}{60} }

 =  \frac{3x}{ \frac{4x}{60} }

 =  \frac{3 \times 60}{4}

 = 3 \times 15

 = 45 km / hr

Hence, the average speed for the entire distance is 45 km/hr.

I HOPE IT'S HELP YOU ☘️

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