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.
During the motion the magnitude of velocity of ram with respect to Shyam is

Options

A. `1 ms^(-1)`
B. `4 ms^(-1)`
C. `5 ms^(-1)`
D. `7 ms^(-1)`

Answer

C

Explanation

c. `vecv_(R,S) = vecv_R - vecv_S - vecv_R + (-vecv_S)`
`|vecv_(R,S)| = sqrt(3^2 + 4^2) = 5ms^(-1)`
`tan theta |vecv_R|/|vecv_S| = 3/4`
Hence, `v = 37%@`