Question

pls solve this...... ...​

Answer 1

Given:

• A car travels 30km at a speed of 40km/hr.
• Again it travels next 30km at a speed of 20km/hr.

To Find :

• Average speed of the car .

Concept Used:

• We will make use of formula of average speed .

Solution :

Total distance covered = (30+30)km =60km.

Speed while first 30km = 40km/hr .

So, time taken = distance/speed = 30/40hr =3/4 hr .

Speed while second 30km = 20km/hr.

So, time taken = distance/speed =30/20hr = 3/2hrs.

Now

Total time taken = 3/4 +3/2 =3+6 /4 = 9/4hrs.

Now ,Formula for average speed is .

$\large{\underline{\red{\boxed{\sf{speed_{avg}=\dfrac{Total\: distance}{Total\:time}}}}}}$

Using this ,

$\sf{v_{avg}=\dfrac{60km}{\dfrac{9hr}{4}}}$

$\sf{v_{avg}=\dfrac{60\times 4}{9hr}}$

${\underline{\red{\sf{\leadsto v_{av}=26.66km/hr}}}}$

Therefore average speed is 26.66km/hr.