The energy of the stars comes from nuclear fusion<span> processes. For stars like the sun which have internal temperatures less than fifteen million Kelvin, the dominant fusion process is </span>proton-proton fusion<span>. For more massive stars which can achieve higher temperatures, the </span>carbon cycle<span> fusion becomes the dominant mechanism. For older stars which are collapsing at the center, the temperature can exceed one hundred million Kelvin and initiate the helium fusion process called the </span>triple-alpha process<span>.</span>
Answer:
k = 101.2 N / m
Explanation:
For this exercise we can use the relationship between work and energy
W = ΔK (1)
Where the work of the friction force is
W = fr x cos θ
As the friction force opposes the movement, the angle is 180º, so the kinetic product remains
W = - fr x
The friction force is given by the equation
fr = μ N
Let's use Newton's second law
Axis y
N - W = 0
N = W
We substitute
fr = μ mg
So the work is
W = - μ m g x
On the other hand, the variation in energy is
ΔEm = Em_final - Em_inicial
ΔEm = ½ k x² - ½ m v²
We substitute in our initial equation 1
-μ m g x = ½ k x² - ½ m v²
k = 2m / x² (- μ g x + ½ v²)
k = 2 2.00 / 0.190² (- 0.660 9.8 0.190 + ½ 2.07²)
k = 101.2 N / m
Just choose the direction and write down the force shown in the arrow. It's too blurry. Can't do it for u. Sorry.
The speed would vary depending on where the molecules are found. Molecules in<span> gas will move faster than they would in liquid.Hope this helps!!</span>