A body moving along a straight line travels one third distance with a velocity 4m/s. The remaining distance is covered with velocity 2m/s for some time t° and with 4m/s for the remaining time. If the average velocity is 3m/s, then the time for which the body moves with velocity 4m/s in second stretch is:
Answers
Answer:
answer is to / 2
Explanation:
let the body travel a total of distance 3L in three unequal parts
like firstly from A to B
given distance travelled is L with velocity 4m/s . let it travel it in t time
so t = L / 4 ( 1 )
now let it travel distance l in time t° to from B to C in given velocity 2m/s
so to = l /2
l = 2t° (2)
now let it travel the remaining distance i.e. 2L - l in time t2 with given velocity 4m/s
so 2L-1 = 4t2
t2 = 2L -l /4 ( 3 )
putting equation (2) in eq. (3)
t2 = 2L - 2t° / 4 (4)
now
given average velocity is 3m/s
total distance / total time = av. velocity
3 = 3L / t + t° + t2
L = t + t° + ( 2L - 2t° ) / 4
L = L/4 + t° +( 2L - 2t° ) / 4
4L = L + 4t° + 2L - 2t°
L = 2t°
putting it in eq (4)
we get
t2 = t°/2