3. Which statement made by a student after examining a rock specimen is an inference?
(1) The rock is of igneous origin.
(2) The rock has rounded edges.
(3) The rock is light-colored.
(4) The rock contains large fragments.

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 ?

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

Individuals who live below the poverty line get seriously ill more often than those who do not what could be the hidden variable in this situation?