Question

Kindly solve the very short questions 4 & 5. And have a look at no 3! Thanks!

For a jet striking a plate at a right angle It can be said that: The fluid forces on the plate will be both parallel and perpendicular to the plate The flow velocity over the plate will differ from one side to the other The flow exiting the control volume will have no component perpendicular to the plate The momentum flux through each side of the control volume is zero Determine the magnitude of the force required to redirect an air jet by 90 degree if the momentum flux caused by the jet coming out of the nozzle is 0.5 N 0.50 N 0.71 N 1.00 N Calculate the air jet flow velocity with the nozzle area of 2 cm^2, if it has to move a 0.5 kg block on a surface with coefficient of friction 0.34. Assume that the jet strikes the block perpendicular to its side and the density of air is 1.2 kg/m^3. 1.7 m/s 3.4 m/s 72 m/s 83 m/s 119 m/s

Answer 1

Here,

3)

For a jet striking at a right angle it can be said that

>> the fluid forces on the plate will be both parallel and perpendicular to the plate.

4)

for the magnetic flux , M = 0.5 N

for the net force = sqrt(0.5^2 + 0.5^2)

net force = 0.71 N

the magnitude of force required is 0.71 N

5)

Area , A = 2 cm^2

mass , m = 0.5 Kg

u = 0.34

let the speed of air needed is v m/s

Using second equation of motion

0.34 * 0.5 * 9.8 - 2 *10^-4 * 1.2 * v^2 = 0

solving for v

v = 83 m/s

the speed of flow is 83 m/s