A horizontal jet of water coming out of a pipe of area of cross-section `20cm^(2)` hits a vertical wall with a velocity of `10ms^(-1)` and rebounds with the same speed. The force exerted by water on the wall is .

Options

A. the thrust exerted by the water on the wall will be doubled
B. the thrust exerted by the water on the wall will be four times
C. the energy lost per second by water strikeup the wall will also be four times
D. the energy lost per second by water striking the wall be increased eight times.

Answer

B, D

Explanation

Thrust = Rate of charge of linear momentum
Thrust = mv where m is mass striking per sec.
`=rho avxxvimplies " " "Thrust" = rhoav^(2)`
Energy lost for second `=(1)/(2)mv^(2)" "=(1)/(2)rho av.v^(2)=(1)/(2)rhoav^(3)`
so option (B,D) are correct.