So I did this lab on momentum on jets and the theory is that "a force is applied on the plate due to change of momentum" the jet both impacted on a flat plate and on a hemispherical plate; now i understand that the greater the angle of deflection of the water jet, the greater the change of momentum. I also understand that the force acting on the hemispherical plate will be double of that acting on the flat plate. I also understand that the force acting on the plate will be equal to the rate of momentum. Now having calculate that change of momentum i got values for both the plate and the hemispherical shell but the results that I obtained show that the rate of change of momentum for the flat is actually double that of the hemispherical shell which is not what the theory predicted and this is where i get confused as the shell deflect the water by 180 degrees whereas the flat plate deflects it by 90 degrees. I then used this formula Fv = Mjgb/a where Mj is the mass of the jockey weight, g is acceleration due to gravity, b the distance of the jockey to the neutral position and "a" the distance from the neutral position to the pivot. And that force Fv is meant to be the vertical force acting on the fluid due to the jockey. The aim to compare the forces acting on the two plates but I'm not sure how to do when the theory is being defied.(adsbygoogle = window.adsbygoogle || []).push({});

PS: i cheated with my other mates and their results showed a similar pattern

someone help please

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Can someone explain the theory of impact of jets?

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**