Question

A car travels 30 km at uniform speed of 40 km/hr and the next 30 km at uniform speed of 20km/hr .find the Average speed​

Answer 1

Answer:

Step-by-step explanation:

the average speed is

(40 + 20)/2 = 30 km/hr

Answer 2

Answer:

A car travels 30 km at a uniform speed of 40 km/h and the next 30 km at a uniform speed of 20km/h, the average speed​ is $26.6km/h$

Step-by-step explanation:

• The average speed of a moving body is defined as the total distance covered by that body divided by the total time

       average speed=total distance/total time

From the question, we have

the distance a car travels in the first half $d_{1} =30km$

speed of the car in this distance $V_{1} =40km/h$

so the time needed for it is given by the formula $t=d/V$

$t_{1} =30/40=0.75s$

second half distance $d_{1} =30km$

speed of that car over here $V_{2} =20km/h$

time taken for it $t_{2} =30/20=1.5s$

the average speed of the car $=\frac{d_{1} +d_{2} }{t_{1} +t_{2} }$

$=\frac{30+30}{0.75+1.5} =60/2.25=26.6km/h$