To test the strength of a retainment wall designed to protect a nuclear reactor, a rocket-propelled F-4 Phantom jet aircraft was crashed head-on into a
concrete barrier at high speed in Sandia, New Mexico, on April 19, 1988. The
F-4 phantom had a mass of 19,100 kg, while the retainment wall's mass was
469,000 kg. The wall sat on a cushion of air that allowed it to move during
impact. If the wall and F-4 moved together at 8.41 m/s during the collision,
what was the speed of the F-4 Phantom upon impact?

The speed of the F-4 Phantom upon impact is approximately 214.92 m/s

Explanation:

The given parameter of the motion of the F-4 Phantom jet aircraft are;

The mass of the F-4 phantom rocket, m₁ = 19,100 kg

The mass of the retaining wall, m₂ = 469,000 kg

The velocity of the combined mass of the wall and the F-4 after collision, v₃ = 8.41 m/s

The retainment wall was initially at rest, therefore, v₂ = 0 m/s

Let 'v₁', represent the speed of the F-4 Phantom upon impact

By the principle of conservation of linear momentum, we have;

m₁·v₁ + m₁·v₂ = m₁·v₃ + m₂·v₃ = (m₁ + m₂)·v₃

Plugging in the values, we have;

19,100 × v₁ + 469,000 × 0  = (19,100 + 469,000) × 8.41

∴ v₁ = (19,100 + 469,000) × 8.41/(19,100) = 214.917329843

v₁ ≈ 214.92

The speed of the F-4 Phantom upon impact, v₁ ≈ 214.92 m/s.

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =