To find the force required to hold the plate against the water stream, we can use the linear momentum equation for a fixed control volume. The linear momentum equation states that the rate of change of momentum within the control volume is equal to the net force acting on the control volume.
In this case, the control volume is the plate and the water jet is the system that is interacting with the plate. The density of water is given as 1000 kg/m3. The velocity of the water jet is 25 m/s and the diameter of the jet is 6 cm, which is equivalent to 0.06 m. The mass flow rate of the water jet can be calculated as follows:
Mass flow rate = Density * Velocity * Area
= 1000 kg/m^3 * 25 m/s * (3.14 * (0.06/2)^2)
= 0.11 kg/s
The momentum of the water jet is equal to the mass flow rate multiplied by the velocity of the jet. The force required to hold the plate against the water stream is equal to the rate of change of momentum of the jet.
Force = Rate of change of momentum
= Mass flow rate * Velocity
= 0.11 kg/s * 25 m/s
= 2.75 N