(a) how much heat transfer (in kj) is necessary to raise the temperature of a 0.190 kg piece of ice from −18.0°c to 134°c, including the energy needed for phase changes? (assume the substance remains at a constant volume throughout each stage of the heating process.) (b) how much time (in s) is required for each stage, assuming a constant 19.0 kj/s rate of heat transfer? (enter your answers as a comma-separated list. enter your times in order from the earliest stage to the final stage of the heating process.)

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 graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.