Question 757565: A started walking in north at 7 am with the speed of 5 km/hr. after one hour B started towards east on a cycle with the speed of 16 km/hr. at what time the distance between them will be 52 km?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A started walking in north at 7 am with the speed of 5 km/hr.
after one hour B started towards east on a cycle with the speed
of 16 km/hr.
at what time the distance between them will be 52 km?
:
Let t = travel time of the bike
then
(t+1) = walking time
:
dist = speed * time
:
This is a pythag problem: a^2 + b^2 = c^2, where
a = 16t, bike dist
b = 5(t+1), walking dist
c = 52, dist apart in t hrs from 8 AM
:
(16t)^2 + (5(t+1)^2 = 52^2
256t^2 + (5t+5)^2 = 2704
256t^2 + 25t^2 + 50t + 25 = 2704
281t^2 + 50t + 25 - 2704 = 0
281t^2 + 50t - 2679 = 0
solve this equation using the quadratic formula
Positive solution t = 3 hrs
At 11 AM they will be 52 km apart
|
|
|
