A+7.00 ? ? c point charge is moving at a constant 9.00×106 m/s in the +y? direction, relative to a reference frame. at the instant when the point charge is at the origin of this reference frame, what is the magnetic-field vector b? it produces at the following points.

enter your answers numerically separated by commas.

bx, by, bz = t

a) x = +0.500m, y = 0, z = 0

b) x = 0,y = -0.500m, z = 0

c) x = 0,y = 0, z = +0.500m

d) x = 0,y = -0.500m, z = +0.500m

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 ?

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air