A problem by Breno Linhares
the scheme above represents the initial instant (t = 0s) of the chase among three vehicles A, B and C, that moving with speed of 50 m/s, 20 m/s and 60 m/s, respectively. Determine how long time, in seconds, it takes until vehicle A is exactly between the vehicles B and C, at middle distance of them.
note: All units are in International System.
The answer is 7.
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1 solution
Start solving the problem in Vehicle A's inertial frame. so velocity of B w.r.t A=-30m/s velocity of C w.r.t A=10m/s now in A's inertial frame A is at rest. Taking the convention left side as negative and right as positive. When A is between B and C, let that equal distance be x now B has to cover x+40 meters with 30m/s and C has to cover x-100 meters with 10m/s in the same time so x+40/30 = x-100/10 obtain x as 170m Put in any one and obtain time as 7 seconds