Answer:
1. C. The change is easily reversible
2. A. a physical change
Explanation:
Happy Holidays
Answer:
a) variation of the energy is equal to the work of the friction force
b) W = Em_{f} -Em₀
, c) he conservation of mechanical energy
Explanation:
a) In an analysis of this problem we can use the energy law, where at the moment the mechanical energy is started it is totally potential, and at the lowest point it is totally kinetic, we can suppose two possibilities, that the friction is zero and therefore by equalizing the energy we set the velocity at the lowest point.
Another case is if the friction is different from zero and in this case the variation of the energy is equal to the work of the friction force, in value it will be lower than in the calculations.
b) the calluses that he would use are to hinder the worker's friction force and energy
W = Em_{f} -Em₀
N d = ½ m v² - m g (y₂-y₁)
y₂-y₁ = 35 -10 = 25m
c) if there is no friction, the physical principle is the conservation of mechanical energy
If there is friction, the principle is that the non-conservative work is equal to the variation of the energy
Correct answer choice is:
b) Solar flares are spots hotter than the surrounding, therefore they are brighter than the rest, and they form where prominences start or end on the surface.
Solar flares eject coronal mass, they eject electrons, protons, and ions from the Sun. They<span> produce high energy particles and radiation that are dangerous to living organisms. </span>The earth encompasses a natural protection against these charged particles. Earth's magnetic field and atmosphere protect us from these particles.
Answer:
O- to track how fast a heart beats
Explanation:
