Ram Shyam are walking on two perpendicular tracks with speed `3ms^(-1) and 4 ms^(-1)`, respectively. At a certain moment (say t = 0s), Ram and Shyam are at 20 m and 40 m away from the intersection of tracks, respectively, and moving towards the intersection of the tracks.
The time t when they are at shortest distance from each other subsequently is -

Options

A. 8.8 s
B. 12 s
C. 15 s
D. 44 s

Answer

A

Explanation

a. `tan 37^@ = 8/(BC)`
`3/4 - 8/(BC)`
`BC = 32/3m`
`sin 53^@ = 80/(3AB), 4/5 = 80/(3xxAB)`
`AB = (100)/3m`
` t = ((32/3 + 100/3))/5 = 132/15 = 8.8s`.