In the distant future, a new planet has been discovered around a nearby Sun-like star. The following information is known about this planet: 1) It has
a density of 4.1 compared to water; ii) its orbital semi-major axis is 1.7 AU;
iii) it has a very thin CO2 atmosphere; iv) imaging of the surface shows an
extensive amount of cratering as well as no liquid water on the surface.
There is evidence of volcanic activity in the distant past. Determine the
following based on the above information:
a) What type of planet is this? (Terrestrial or Jovian)

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 ?

Phase changes are chemical changes. true or false

An electron is traveling with initial kinetic energy k in a uniform electric field. the electron comes to rest momentarily after traveling a distance d. (a) what is the magnitude of the electric field