Discuss the below:
Q1) Galaxy A is found to be receding from us with a speed of 0.8c. Galaxy B I found to be receding from us with a speed of 0.4c. (a) What is our velocity as seen from galaxy A? (b) What is velocity of galaxy B as seen from galaxy A, if both are seen in the same direction in space? (c) What is the velocity of galaxy B as seen from galaxy A, if they are seen in exactly opposite directions in space?
Q2) The rest energy and total energy, respectively of three particles are (1) m, 2m; (2) m, 3m; (3) 3m, 4m. Rank the particles according to (a) their mass, (b) their kinetic energy and (c) their speed, greatest first.
Q3) The following metals are used in an experiment in which light is incident on the metal surface: Al (?= 4.08), Cu (?= 4.70), Zn (?= 4.31) and Na (?= 2.28). (a) Rank the metals according to the cutoff frequency, greatest first. (b) Rank the metals according to the cutoff wavelength, greatest first. (c) Rank the metals according to the maximum KE of the emitted electrons for a wavelength, λ, greatest first. (Assume λ<λc).
Q4) The values of E and E' are given for four different situations in which a photon is Compton scattered from a stationary electron (a) 2E, E (b) 2E, ½E (c) E, ½E and (d) 2E,1½E. (a) Rank according to the max Δλ of the photon, greatest first. (b) Rank according to the max KE of the electron, greatest first. (c) Rank according to the angle of scattering of the photon, greatest first.
Q5) Rank the following particles according to the minimum uncertainty in position, greatest first,
(a) m = m (b) m = 2m (c) m = ½m (d) m = 3/2m
Δv = Δv Δv = Δv Δv = ½Δv Δv = 1/3Δv
Q6) Rank the alpha decay of the following isotopes according to the Q value, greatest first. Th 232, U 238, Rn 220, and Ac 222.
Q7) (a) Indicate the type of decay (+β, -β or EC) for each of the following decays. (b) Rank each of the following decay according to the Q value, greatest first.
(a) ¹9O-- →¹9F + (e-) + v
(b) ¹76Lu--→¹76Hf + ( e-) + v
(c) ²5Al---→²5Mg + (e+) + v
(d) ¹²4I--→¹²4Te + (e+) + v
(e) ¹5O + (e-)--→¹5N + v
(f) ¹70Tm + (e-)--→¹70Er + v
Q8) ³²P (lifetime = 14.3 days) is used as a biochemical tracer. A solution containing this phosphorus isotope is fed to a tomato plant; its leaves are harvested and measured for phosphorus 3.5 days later. By what factor should the count reading be corrected to obtain the phosphorus concentration in the leaves?
Q9) At an electron-positron storage ring, two beams of equal energy and opposite momentum are made to collide repeatedly. The reaction (e+)(e-)→(μ+)(μ-) is observed. The μ has a mass of 106MeV. (a) What is the minimum total energy in the beams for the reaction to occur? (b) If the electron and positron beams have energies of 200MeV, what is the energy, momentum and velocity of the outgoing muons? (c) if the electron and positron beams have energies of 200MeV, and the muon lifetime at rest is 2.2 μs, how long will the muons survive in the laboratory?