Question

on a 120km track a train travels first 30km at a uniform speed of 30 km/hr.How fast must the train travels to the next 90 km so as to average 60km/hr of the entire trip.​

Answer 1

Answer:

Hence, the train must travel the next 90 km at the speed of 90 km/hr so as to have an average of 60 km/hr for the entire journey.

Answer 2

answer:

90km/he

explanation:

Average speed=Total distance Total time taken

Vav=d/tort =d/Vav

For 120 km,

t= 120km/60 km/hr

=2 hr

For 1st 30 km,

t1= 30 km/hr/30km

=1 hr

For remaining 90 km,

t2=t−t1

=2−1

=1 hr

speed=distance/time or v2=d2/t2

=90/1

=90 km/hr