Two particles are projected with speed `4 m//s` and `3 m//s` simultaneously from same point as shown in the figure. Then :

Options

A. Their relative velocity is along horizontal direction.
B. Their relative acceleration is non-zero and it is along vertical direction.
C. They will hit the surface simultaneously.
D. Their relative velocity is constant and has magnitude `1.4 m//s`

Answer

D

Explanation

`vec(v)_(A) = 4cos 53hat(i) +4sin53^(@)hat(j)`
`vec(v)_(B) = 3cos 37hat(i)+3sin37^(@)hat(j)`
`vec(v)_(A) = (12)/(5)hat(i)+(16)/(5)hat(j)`
`vec(v)_(B) = (12)/(5)hat(i)+(9)/(5)hat(j)`
`vec(v)_(A//B) implies(7)/(5)hat(j)=1.4m//shat(j)`