Two trains are each $$50\,m$$ long moving parallel towards each other at speeds $$10\,m/s$$ and $$15\,m/s$$ respectively. After what time will they pass each other?
A.
$$5\sqrt {\frac{2}{3}} \sec $$
B.
$$4\,\sec $$
C.
$$2\,\sec $$
D.
$$6\,\sec $$
Answer :
$$4\,\sec $$
Solution :
Relative speed of each train with respect to each other be, $$v = 10 + 15 = 25\,m/s$$
Here distance covered by each train = sum of their lengths $$= 50 + 50 = 100\,m$$
$$\therefore {\text{Required time}} = \frac{{100}}{{25}} = 4\,\sec $$
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