We will apply the concepts related to Newton's second law. At the same time we will convert everything to the system of international units.

The values of the velocities are,


We know that the acceleration is equivalent to the change of the speed in a certain time therefore



Now applying the Newton's second law we have,



Therefore the approximate magnitude is 8516.36N
I don't really know what it's about but everything looks okay to me. There might be some mistakes on the last sentence but i'm not completely sure.
The correct answer is
A. Chain reaction
This is how the chain reaction works in a process of nuclear fission:
1) Slow-moving neutrons reach heavy, unstable, radioactive nuclei (such as Uranium-235)
2) The neutrons interact with the nuclei of Uranium, which break apart producing smaller nuclei and additional neutrons
3) The neutrons produced in the reaction are slowed down by a moderator (e.g. water) and they interact with new nuclei of Uranium, causing new fission reactions)
4) The new neutrons interact with new nuclei of Uranium, and so on...
Answer:
301.48 J/s
Explanation:
We are given;
Temperature of the sky dropping to −40∘C: T_o = -40°C = -40 + 273 = 233 K
Temperature of your skin and clothes: T = 30°C = 30 + 273 = 303 K
Body surface area of human body is around 2 m². But here only half of the body is facing the sky, Thus Area is: A = 2/2 = 1 m²
To solve this, we will use the equation for thermal heat transfer known as the Stefan bolt Mann equation.
ΔQ/Δt = εσA(T⁴ - (T_o)⁴)
Where;
ΔQ/Δt is the rate at which you body loses energy by radiation
ε is the emissivity of the human body with a value of 0.97
σ is Stefan boltzmann constant with a value of 5.67 X 10^(-8) W/m².K⁴
Thus;
ΔQ/Δt = 0.97 × 5.67 X 10^(-8) × 1(303⁴ - 233⁴)
ΔQ/Δt = 301.48 J/s