Answer:The first task of a nuclear weapon design is to rapidly assemble a supercritical mass of fissile uranium or plutonium. A supercritical mass is one in which the percentage of fission-produced neutrons captured by another fissile nucleus is large enough that each fission event, on average, causes more than one additional fission event. Once the critical mass is assembled, at maximum density, a burst of neutrons is supplied to start as many chain reactions as possible. Early weapons used a modulated neutron generator codenamed "Urchin" inside the pit containing polonium-210 and beryllium separated by a thin barrier. Implosion of the pit crushed the neutron generator, mixing the two metals, thereby allowing alpha particles from the polonium to interact with beryllium to produce free neutrons. In modern weapons, the neutron generator is a high-voltage vacuum tube containing a particle accelerator which bombards a deuterium/tritium-metal hydride target with deuterium and tritium ions. The resulting small-scale fusion produces neutrons at a protected location outside the physics package, from which they penetrate the pit. This method allows better control of the timing of chain reaction initiation.
Explanation:
Methods Of Separating Mixtures
Handpicking.
Threshing.
Winnowing.
Sieving.
Evaporation.
Distillation.
Filtration or Sedimentation.
Separating Funnel.
Answer:
A
Explanation:
it has an arrow symbolizing direction because a vector quantity has both magnitude and direction.
D. Drop in barometric pressure, warm ocean water, humid air. The low pressure brings in a cool air mass causing collision of two different masses.
My father rode out a typhoon near Okinawa WWII, onboard the battleship USS Missouri BB-63.
Violent pitching, alarms going off for approaching capsize pitch. The captain came on loudspeaker “ don’t worry men, land is near... about a mile straight down”.
Q = mcΔT = (4.00 g)(0.129 J/g•°C)(40.85 °C - 0.85 °C)
Q = 20.6 J of energy was involved (more specifically, 20.6 J of heat energy was absorbed from the surroundings by the sample of solid gold).
