Water is flowing in a pipe of diameter 4 cm with a velocity `3 m//s` . The water then enters into a tube of diameter 2 cm . The velocity of water in the other pipe is

Options

A. 3 m/s
B. 6 m/s
C. 12 m/s
D. 8 m/s

Answer

C

Explanation

`A_1 v_1 = A_2 v__2`
`implies pi r_1^2 xx v_1=pi r_2^2 xx v_2 implies pi(2)^2xx3=pi(1)^2 xx v_2`
`implies 4xx3=1xx v_2 implies v_2=12 m//s`