Two people start at the same place and walk around a circular lake in opposite directions. One has an angular speed of 1.80E-3 rad/s, while the other has an angular speed of 3.60E-3 rad/s. How long will it be before they meet?
Do I use w = 2(pi)/T?
Thanks!
2007-11-20 07:29:53 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The circumference of the lake is 2*pi radians
which is the sum of the distance traveled by the walkers, so
(1.8+3.6)*t/1000=2*pi
solve for t
t=2000*3.14/5.4
19 min and 23 seconds
j
2007-11-20 07:46:18 · answer #1 · answered by odu83 7 · 0⤊ 0⤋
This example assumes that "opposite directions" means opposite angular direction (ie., one walks clockwise and the other walks counter-clockwise).
Instead of thinking about two people walking toward each other, change it so that one person is standing still and the other is walking at the relative angular velocity between them (the sum of their velocities). The person moving has to travel half a circumference (180 degrees or pi radians). Just figure out how long it takes the person to travel that "distance" with the resulting angular velocity.
angle = angular velocity * time --->
time = angle / angular velocity
time = pi / (0.0018 + 0.0036)
time = 582 seconds = 9.70 minutes
2007-11-20 07:56:51 · answer #2 · answered by Anonymous · 0⤊ 0⤋