Answer:
3.33 seconds
Explanation:
We can use the velocity formula [ v = u + at ] to solve.
Find the value "u".
135km/h -> 135km*1000m/3600s -> 37.5m/s
Find the value "v".
75km/h -> 75km*1000m/3600s -> 20.83m/s
Keep in mind we are dealing with "deceleration" so when we input 5.0m/s into the formula, it will be a negative value.
Now, find "t" which is the value we aren't given with the values we're given in the question.
20.83 = 37.5 - 5t
-16.67 = -5t
3.33 = t
Best of luck!
The whiter the color the more young it is and the more energy it emits
Answer:
Explanation:
The direction of propagation of electromagnetic wave
is given by the direction of vector E x B where E is electrical field , B is magnetic field .
Given Electric field = E i because it is along x axis
Magnetic field = Bj because it is along y axis
E x B = Ei x Bj
= EB k .
so direction of E x B is along k direction or z - axis so wave is propagating along z - axis .
Answer:
Amplitude—distance between the resting position and the maximum displacement of the wave
Frequency—number of waves passing by a specific point per second
Period—time it takes for one wave cycle to complete
wavelength λ - the distance between adjacent identical parts of a wave, parallel to the direction of propagation.
Tension - described as the pulling force transmitted axially by the means of a string, a cable, chain, or similar one-dimensional continuous object, or by each end of a rod, truss member, or similar three-dimensional object
Answer:
λ = 102.78 nm
This radiation is in the UV range,
Explanation:
Bohr's atomic model for the hydrogen atom states that the energy is
E = - 13.606 / n²
where 13.606 eV is the ground state energy and n is an integer
an atom transition is the jump of an electron from an initial state to a final state of lesser emergy
ΔE = 13.606 (1 / - 1 / n_{i}^{2})
the so-called Lyman series occurs when the final state nf = 1, so the second line occurs when ni = 3, let's calculate the energy of the emitted photon
DE = 13.606 (1/1 - 1/3²)
DE = 12.094 eV
let's reduce the energy to the SI system
DE = 12.094 eV (1.6 10⁻¹⁹ J / 1 ev) = 10.35 10⁻¹⁹ J
let's find the wavelength is this energy, let's use Planck's equation to find the frequency
E = h f
f = E / h
f = 19.35 10⁻¹⁹ / 6.63 10⁻³⁴
f = 2.9186 10¹⁵ Hz
now we can look up the wavelength
c = λ f
λ = c / f
λ = 3 10⁸ / 2.9186 10¹⁵
λ = 1.0278 10⁻⁷ m
let's reduce to nm
λ = 102.78 nm
This radiation is in the UV range, which occurs for wavelengths less than 400 nm.