Two towns A and B are connected by a regulaar bus service with a bus leaving in either direction every T min A man cycling with a speed of 20 km h^(-1) in the direction A to B notices that a nus goes past him every 18 min in the direction of his motion, and every 6 min in the opposite direction. What is the perild T of the bus service and with what speed (assumed constant )do the buses ply on the road?
Answers
Answered by
6
Answer:
Hello!
Let speed of bus = V
relative speed when cylist and bus both move same direction = (V - 20) km/h
We know ,
Distance = speed x time
A/C to question ,
Bus went past cyclist every 18min when in the motion of his direction .
e.g distance covered by bus = ( V-20) x 18/60 km
Every T time bus travels distance = VT
e.g. ( V - 20) x 18/60 = VT ----------(1)
Similarly ,
Relative speed of bus when bus and cyclist move in opposite direction = ( v+ 20) km/h
Bus went past every 6 min in opppsite direction of his motion .
then,
( V + 20) x 6/60 = VT ----------(2)
Solve both equation ,
( V -20)x 18/60 =( V +20) x 6/60
=> 3V - 60 = V + 20
=> 2V = 80
=> V = 40 Km/h put equation (1)
(40 - 20)x18/60 = 40T
T = 6/40 hour = 9 min
Hence,
V= 40 km/h and T = 9 min
hope it helps..
Similar questions