Question

A body travels one-third distance with velocity
15 ms-1 and remaining two-third distance with
20 ms-1, then average velocity of the body is
(1) 9 ms-1
(2) 18 ms-1
(3) 6 ms-1
(4) 5 ms-1 1​

Answer 1

Answer:

find the smallest volume of oxygen needed to burn 1dm3 of ethane completely

Answer 2

Answer:

let total distance=3x

so body travels x distance with velocity 15m/s

lly 2x distance with velocity 20m/s

so average velocity= total distance/total time=3x /t+T .............(1)

here t= distance/ velocity= x/15

lly T= 2x /20

now put these values in (1)

ave. vel.= 3x/{x/15+2x/20}=18m/s