Question

a particle travels half of the distance of a straight journey with a speed 6 m/s . the remaining part of the distance is covered with a speed 2 m/s for half of the time of remaining journey and with speed 4 m/s for other half of time . the average speed of particle is

Answer 1

Average speed of particle= Total sum of speed of particle/No. of parts
                                        =(6+2+4)/3
                                        =12/3=4

Answer 2

Let total distance=d Total time=T Then in d/2....... t1=d/6 t2=d/(4*4.5) + d/(4*7.5) =4d/45 T=t1+t2=d/6+4d/45 =23d/90 Average speed =t. Dis/t. Time= d/T =3.91 m/s........ANS All the best!!!!!