81. 82. 83. An electron is in the ground state of Tritium for which the nucleus consists of a proton and two neutrons. A radioactive nuclear reaction suddenly occurs in which the Tritium nucleus gets converted into an isotope of Helium. The probability that the electron remains in the ground state of "He" will be A) 128 B) C) 729 512 729 256 D) 729 A satellite is in elliptical orbit about the earth. At pen gee it has an altitude of 1100 km and at apogee its altitude is 4100 km. The major axis of the orbit is A) 10400 km B) 18000 km C) 11600 km D) 5200 km A mass M moves with speed V in x direction. It explodes into two pieces that go off at angles and 2 respectively. The magnitudes of the momenta of the two pieces are (Here P = MV = momentum of the mass M) A) P = B) P = C) P = D) P = P sin 02 sin(01+02) P cos 02 sin(0+82) P sin 82 cos(81+82) P cos 02 cos(0+02) and P = and P = and P and P == P sin 01 sin(01+02) P cose sin(0+02) P sin 01 cos(01+82) P cos 01 cos(01+82) 84. Two identical springs with same spring constant "k" are stretched to length l >> lo their unstretched length lie in the x direction and have mass m between them. The other end of either spring ends up in rigid support The ratio of the natural frequency for small oscillations in the x direction to that in the y direction will be A) (1-4) -1/2 B) Lo C) 85. D) (1-10) The drawing shows loud speakers A and Band a point C, where a listener is positioned. Both speakers vibrate in phase and are playing a 68.6 Hz tone. The speed of sound 343 m/s. The closest to speaker A the speaker can be located so that no sound is heard is 1 m 60 4) B A) 2.00 m B) 0.59 m C) 2.89 m D) 3.89 m