Abeam of ag atoms, each with spin-1/2, is prepared in a way that 60% of the atoms are in the sz = +ħ/2 eigenstate of sz, and 40% are in the eigenstate sx = -ħ/2 of sc. (a) obtain the density matrix at t = 0, in the basis of eigenstates of sz. (b) admit that the atoms are subjected to a magnetic field b = boû, so that the hamiltonian reads, h = us. b (u is the magnetic moment of an atom). obtain the density matrix at time t, in the basis of eigenstates of sz. (c) calculate (sz) at times t = 0 and t.

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.