Question

A car travels with speed 3 ms-1 for the first half
distance of the journey and with speed 6 m s -1 for
the remaining half. What is the average speed of
the entire journey?
[NCERT Pg. 42]
(1) 6 m s-1
(2) 18 m s-1
(3) 9 m s-1
(4) 4 ms-1​

Answer 1

Answer:

given =   speed (v) = 3ms⁻¹

             speed (v) = 6ms⁻¹

to find =  avarage speed = ?

solution =

     avarage speed = total distance covered / total time taken

if the total distance is d then,

              t₁ = d/6 sec

and         t₂= d/2/6 = d/12

so,avarage speed= dm/ d/6+ d/12

V avg= 4m/s

so,the avarage speed of entire journey is 4ms⁻¹