Via half-life equation we have:
Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:
There is 6.25 grams left of Ra-229 after 12 minutes.
Answer:
the reflected wavelength is lano = 4.55 10⁻⁷ m which corresponds to the blue color
Explanation:
This is a case of reflection interference, we must be careful
* There is a 180º phase change when light passes from the air to the soap film (n = 1,339), but there is no phase change when passing from the pomp to the plastic (n = 1.3)
* the wavelength within the film is modulated by the refractive index
λₙ = λ₀ / n
if we consider these relationships the condition for constructive interference is
2 t = (m + ½) λₙ
2t = (m + ½) λ₀ / n
λ₀ = 2t n / (m + ½)
we substitute the values
λ₀= 2 255 10⁻⁹ 1,339 / (m + ½)
λ₀ = 6.829 10⁻⁷ (m + ½)
let's calculate the wavelength for various interference orders
m = 0
λ₀ = 6.829 10⁻⁷/ ( 0 + ½ )
λ₀ = 13.6 10⁻⁷
it is not visible
m = 1
λ₀ = 6,829 10⁻⁷/ (1 + ½)
λ₀ = 4.55 10⁻⁷
color blue
m = 2
λ₀ = 6.829 10⁻⁷ / (2 + ½)
λ₀ = 2,7 10⁻⁷
it is not visible
therefore the reflected wavelength is lano = 4.55 10⁻⁷ m which corresponds to the blue color
Jennifer
Explanation:
she has more mass which means she is using more force
Metal as it is a conductor of electricity
Answer: I = 9.0 A
Explanation: <u>Ohm's</u> <u>Law</u> is defined as the relationship between voltage and current: in a circuit, the voltage accross a conductor is directly proportional to the current.
The constant of proportionality is Resistance, whose unit is ohm (Ω).
so, Ohm's Law is
V = R.I
It is asked for the current, so, rearraging:
When added two more batteries, the voltage of the circuit triples:
Since they are directly proportional, if voltage triples, so does current:
9.0
The new current, when driven by 3 batteries is 9.0 A.
