bonsoir, je peux vous aider avec les maths laissez-moi comprendre merci
I believe the correct answer is false. <span>The entropy of an isolated system must not be conserved, so it changes. Entropy always tend to increase and tend to favor change. Entropy is a measure of disorderliness of a system.</span>
Answer:
Explanation:
mass of balloon (m) = 12.5 g = 0.0125 kg
density of helium = 0.181 kg/m^{3}
radius of the baloon (r) = 0.498 m
density of air = 1.29 kg/m^{3}
acceleration due to gravity (g) = 1.29 m/s^{2}
find the tension in the line
the tension in the line is the sum of all forces acting on the line
Tension =buoyant force + force by helium + force of weight of rubber
force = mass x acceleration
from density = \frac{mass}{volume} , mass = density x volume
- buoyant force = density x volume x acceleration
where density is the density of air for the buoyant force
buoyant force = 1.29 x (\frac{4]{3} x π x 0.498^{3}) x 9.8 = 6.54 N
- force by helium = density x volume x acceleration
force by helium = 0.181 x (\frac{4]{3} x π x 0.498^{3}) x 9.8 = 0.917 N
- force of its weight = mass of rubber x acceleration
force of its weight = 0.0125 x 9.8 = 0.1225 N
- Tension = buoyant force + force by helium + force of weight of rubber
the force of weight of rubber and of helium act downwards, so they
carry a negative sign.
- Tension = 6.54 - 0.917 - 0.1225 = 5.5 N
Answer:
A λ = 97.23 nm
, B) λ = 486.2 nm
, C) λ = 53326 nm
Explanation:
With that problem let's use the Bohr model equation for the hydrogen atom
= -k e² /2a₀ 1/n²
For a transition between two states we have
- = -k e² /2a₀ (1/ ² - 1 / n₀²)
Now this energy is given by the Planck equation
E = h f
And the speed of light is
c = λ f
Let's replace
h c / λ = - k e² /2a₀ (1 / ² - 1 / no₀²)
1 / λ = - k e² /2a₀ hc (1 / ² -1 / n₀²)
Where the constants are the Rydberg constant = 1.097 10⁷ m⁻¹
1 / λ = (1 / n₀² - 1 / nf²)
Now we can substitute the given values
Part A
Initial state n₀ = 1 to the final state = 4
1 / λ = 1.097 10⁷ (1/1 - 1/4²)
1 / λ = 1.0284 10⁷ m⁻¹
λ = 9.723 10⁻⁸ m
We reduce to nm
λ = 9.723 10⁻⁸ m (10⁹ nm / 1m)
λ = 97.23 nm
Part B
Initial state n₀ = 2 final state = 4
1 / λ = 1.097 10⁷ (1/2² - 1/4²)
1 / λ = 0.2056 10⁻⁷ m
λ = 486.2 nm
Part C
Initial state n₀ = 3
1 / λ = 1,097 10⁷ (1/3² - 1/4²)
1 / λ = 5.3326 10⁵ m⁻¹
λ = 5.3326 10-5 m
λ = 53326 nm
The total kinetic energy before the collision is not equal to the total kinetic energy after the collision. A portion of the kinetic energy is converted to other forms of energy such as sound energy and thermal energy. A collision in which total system kinetic energy is not conserved is known as an inelastic collision.