Answer: rate at which energy is being removed is 58.9J/s or 58.9W
Explanation:
Given;
Mass of water Mw =892g = 0.892kg
Mass of aluminium Ma = 214g = 0.214kg
Rate of change in temperature ∆T = 0.9°C per minute
Specific heat capacity of water Cw = 4186J/kgC
Specific heat capacity of aluminium Ca = 900J/kgC
Since both the water and aluminium are at thermal equilibrium and the decrease with the same rate, the energy removed per minute is given as;
Q = (MwCw + MaCa)∆T
Q = (0.892×4186 + 0.214×900)×0.9
Q = 3533.8608J per minute
To determine the energy being removed in watts
P = Q/t
P = 3533.8608J/60s
P = 58.89768W
P = 58.9W
Answer:
A) E = 3.75 10⁻⁴ J
, B) P = 1.25 10⁻¹² Pa, C) λₙ = 604.48 10⁻⁹ m
= 604 nm, D) f = 3.7 10¹⁴ Hz
, E) E₀ = 2,148 10⁴ N /C, F) B₀ = 7.16 10⁻⁹ T
Explanation:
Let's reduce the magnitudes to the SI system
λ = 810 nm = 810 10⁻⁹ m
P = 250 mW = 250 10⁻³ W = 0.250 W
d = 510 um = 510 10⁻⁶ m
A) The power is defined
P = W / t = E / t
E = P t
E = 0.250 1.50 10⁻³
E = 3.75 10⁻⁴ J
B) The radiation pressure is
P = E / c
P = 3.75 10⁻⁴ / 3 10⁸
P = 1.25 10⁻¹² Pa
C) the speed of light is given by
c = λ f
The frequency does not change when moving from one medium to another, resonant processes, therefore to maintain the speed of light in the material medium we have
v = λₙ f
We divide the two expressions
c / v = λ / λₙ
Let's use
n = c / v
λₙ = λ / n
λ = 810 10⁻⁹ / 1.34
λₙ = 604.48 10⁻⁹ m
λₙ = 604.48 nm
D) the passage of radiation from one medium to another is a resonant type process where the radiation excites the electrons that decay emitting at the same frequency
f = c / λ
f = 3 10⁸/810 10⁻⁹
f = 3.7 10¹⁴ Hz
E) In this part let's use the radiation intensity ratio
I = E₀² /μ₀ c
E₀ = √ I μ₀ c
Intensity is defined
I = P / A
In circle area is
A = π r² = π d² / 4
We replace
E₀ = √ (μ₀ c P 4/πd²)
E₀ = √ (4π 10⁻⁷ 3 10⁸ 0.250 4 /π (510 10⁻⁶)²)
E₀ = √ 4.6136 10⁸
E₀ = 2,148 10⁴ N /C
F) to find the magnetic field let's use that the fields are in phase
c = E₀ / B₀
B₀ = E₀ / c
B₀ = 2,148 10⁴/3 10⁸
B₀ = 7.16 10⁻⁹ T
Answer:
5 cm
Explanation:
We are given that,
The density of metal = 8 g/cm^3
The Mass of the Solid Cube = Mass of the metal = 1 kg = 1000 g
We know that,
Density = Mass / Volume
8 = 1000 / V
Hence, as the volume of the solid cube is 125 cm^3, its side will be the volume's cube root which is 5 cm
Answer:
Stretch and moving away from us, with more distant ones moving faster
Explanation:
Astronomers observed that the entire universe is getting bigger because distant galaxies appears to be moving away from us
