A horizontal spring has one end firmly attached to a wall and the other end attached to a mass. The mass can slide freely on a smooth, horizontal surface with no friction. The mass is pulled away from the equilibrium position by a distance A in the positive x-direction and then released. At which position is the kinetic energy of the mass-spring system a maximum?

The “death throes” of stars are amongst the most complex phenomena in all of astronomy, and the “corpses” of stars amongst the most energetic and exotic objects in existence. beginning at the end of the core helium fusion stage in a star’s life, describe in detail the post-main sequence development of both (a) a 1.0 solar mass star, and (b) a 25.0 solar mass star. in what significant ways do they differ? what role does each of these types of stars play in the "star-gas-star" cycle and the evolution of chemical elements in our galaxy?

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 dissociation energy of a molecule is the energy required tobreak apart the molecule into its separate atoms. the dissociationenergy for a particular molecule is 5.48 x 10-18 j. suppose that this energy is provided by a single photon. determinethe (a) wavelength and (b) frequency of the photon