Recent content by whereisnomar

Homework Statement Find the centroid of the hemisphere, z=sqrt(a-x^2-y^2). Homework Equations z(bar)=(1/m)* Surface integral(z dS) dS= magnitude of the magnitude of normal vector * dA The Attempt at a Solution I use the gradient to the hemisphere to get the magnitude of the normal...

http://galileoandeinstein.physics.virginia.edu/lectures/synchronizing.html" the website talks about synchronizing clocks on a moving train. But I have a few questions about it: 1) Why are you allowed to add ct+vt on the left-hand side of the first equation below the picture of the train? I...