1. Which equation shows a strong acid dissolving in water? a. CH3COOH + H2O + CH3COO-+H307
b. NaOH + H2O → Na + OH+H2O
c. HNO3 + H20 H30* + NO3
d. NH3 + H2O → NH + OH

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 ?

Stars x and y are both bluish main sequence stars. star x has a higher absolute brightness than star y. how do the two stars compare? explain

A110-pound person pulls herself up 4.0 feet. this took her 2.5 seconds. how much power was developed? 0.13 hp 0.32 hp 2.0 hp 3.1 hp