Desmond wanted to paint his bedroom. He went to the hardware store and was shown a variety of different paint colors from which to pick. Paint is an example of an example of which kind of product, which is made with chemicals by human? A. natural B. synthetic
C. accidental
D. natural resource

Space-time metric ds2= -dt2+at2dx2+bt2dy2+ct2dz2 (a)how does the area of a rectangle with vertices at ( x=0, y=0, z=0 ), (1,0,0 ), ( 0,1,0 ) and (1,1,0 ) changes with time? (b) if a photon moving in the x direction starts from the origin at t=1, when does it reach x=l? (ds=0 for the trajectory of a photon.) (c) the proper time for a particle is defined by cd=ds. what is the proper time for a particle to move along the trajectory ( x(t)=t, y(t)=0, z(t)=0 ) from t=0 to 1 ? what is the condition on the parameter a so that the velocity of the particle never exceeds the speed of light ?

The a metal retainer that keeps the rolling elements evenly spaced. n a. seal n b. separator n c. bearing n d outer race

The energy equivalent of the rest mass of an electron is