Directions : In the following question more than one of the answers given may be correct. Select the correct answer and mark it according to the code:
A liquid of density p comes out with a velocity v from a horizontal tube of area of cross-section A. The reaction force exerted by the liquid on the tube is F, then: (1) \[F\propto \rho \] (2) \[F\propto A\] (3) \[F\propto {{v}^{2}}\] (4) \[F\propto v\]A) 1 and 2 are correct
B) 2 and 3 are correct
C) 1 and 4 are correct
D) 1, 2 and 3 are correct
Correct Answer: B
Solution :
Volume of the liquid flowing out per second\[=A\times v\] Mass of this liquid \[=Av\times \delta \] Momentum of this liquid\[=Ave\times v=A\rho {{v}^{2}}\] So, rate of change of momentum = forces (F) \[=A\rho {{v}^{2}}\] i.e., \[F=A\rho {{v}^{2}}\] i.e., \[F\propto \rho ,\]of\[F\propto A\]or\[F\propto {{v}^{2}}\]
You need to login to perform this action.
You will be redirected in
3 sec
