For Youngs modulus stress is force per unit area but for bulk modulus it is change in pressure why? And what is the difference between stress and pressure? And my text book says "when the deformed body is at REST stress must be equal and opposite to deforming force power unit area" my question is what will happen if the body is in motion?

Question

For Youngs modulus stress is force per unit  area but for bulk modulus it is change in pressure why? And what is the difference between stress and pressure? And my text book says "when the deformed body is at REST stress must be equal and opposite to deforming force power unit area" my question is what will happen if the body is in motion?

anonymous · Answer

##sorry deforming force PER unit area

anonymous · Answer

@theyatin @sami-21

anonymous · Answer

get your hands on Elasticity forEngineers and physicists, or any Video onyoutube OR free tutorial. This is not something one can reasonably answer here.

anonymous · Answer

Please I couldn't get to the right source yet so please help ..even few words about it would help me

anonymous · Answer

attachment

anonymous · Answer

VERY short and VERY LUCID EXPLANATION is given there

anonymous · Answer

ANd this here is DOWNRIGHT CLEAR and GREAT http://www.antonine-education.co.uk/Pages/Physics_2/Solid_Materials/MAT_03/Materials_3.htm

experimentx · Answer

if the deforming force is greater, then it will cause motion such that it deform (compresses) even more until force is balanced ... and if deforming force is lessened, the  the deforming force will cause motion so that it expands out ,, until forced is balanced.

experimentx · Answer

in a closed and constrained system, when ever forces are balanced, there is no motion.

anonymous · Answer

thx for the mdl

anonymous · Answer

Ok here we go if a moving object is deformed by an external force will this deforming force per unit area = stress hold or will there be any changes...was my question..

anonymous · Answer

My simple explanation for your question would be Young modulus considers stress in linear length..that is the force exerted on a liniear dimension(i.e F/A) but bulk modulus considers deformation in all dimensions of the given body(e.g a box) which affects the volume of that body, so these forces are perpendicular to the area of say the box and we know from bulk modulus stress is F/A and recall from pressure units that a force acting on a particle perpendicular over area is pressure..right?,so you conclude that forces in all direction of that given body acting perpendicularly over that body is "pressuring" the object....so simple conclusion the stress is the change in pressure acting over the body. for more on pressure refer "physics for scientists and Engineers" and you can watch this video on young's modulus http://www.youtube.com/watch?v=YrRP-oGPjvk