Math Is Fun Forum

missbossyy

Member

Registered: 2008-02-01

Posts: 38

confused

Trains A and B face each other on adjacent parallel tracks. They are initially 400 meters

apart and at rest. Train A accelerates at 1.4 m/s2 to the right and train B accelerates at 2.2

m/s2 to the left.

(A) Calculate the time it takes the trains to pass each other.

(B) Calculate how far train A has traveled during this time interval.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: confused

After t seconds, train A has moved 0.5×1.4×t[sup]2[/sup] metres while train B has moved 0.5×2.2×t[sup]2[/sup] metres. When they pass each other, the sum of the distances they have travelled is equal to their original distance apart, i.e.

Solve that for t.

Then plug in that value of t into 0.5×1.4×t[sup]2[/sup] to find the distance A has moved.
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missbossyy

Member

Registered: 2008-02-01

Posts: 38

Re: confused

THANKS FOR THE TIME IT TOOK YOU TO HELP ME :-) i APPERICATE IT !