3 is the answer teeeeeeeeeheeeeeeeee
Answer:
Ф = 2.179 eV
Explanation:
This exercise has electrons ejected from a metal, which is why it is an exercise on the photoelectric effect, which is explained assuming the existence of energy quanta called photons that behave like particles.
E = K + Ф
the energy of the photons is given by the Planck relation
E = h f
we substitute
h f = K + Ф
Ф= hf - K
the speed of light is related to wavelength and frequency
c = λ f
f = c /λ
Φ =
let's reduce the energy to the SI system
K = 0.890 eV (1.6 10⁻¹⁹ J / 1eV) = 1.424 10⁻¹⁹ J
calculate
Ф = 6.63 10⁻³⁴ 3 10⁸/405 10⁻⁹ -1.424 10⁻¹⁹
Ф = 4.911 10⁻¹⁹ - 1.424 10⁻¹⁹
Ф = 3.4571 10⁻¹⁹ J
we reduce to eV
Ф = 3.4871 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
Ф = 2.179 eV
The distance covered is 25.9 m.
<h3>How deep is the cave?</h3>
We know that the speed of sound refers to the speed with which an sound moves in an object.
Given that;
speed of sound = 345m/s
Time taken = 0.15s
We know that;
v = 2d/t
v = speed of sound
d = distance
t = time taken
vt = 2d
d = vt/2
d = 345m/s * 0.15s/2
d = 25.9 m
Learn more about speed of sound:brainly.com/question/15137350
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Answer:
B
Explanation:
From Newton's law of motion, we have:
V^2 = U^2 + 2gH
Where V and U are final and initial velocity respectively.
H is the height.
For the object to have a sustain a maximum height it means the final velocity of the object is zero.
By computing the height of the object sustain by A, we have:
0^2 = 2^2 -2×10×H
0= 4 -20H
4 = 20H;
H= 0.2m
For object B we have;
0^2 = 1^2 -2×10×H
0 = 1 -20H
H = 1/20= 0.05m
From computing the height sustain by both objects, we see object B is projected at a shorter height into atmosphere than A.
Hence object B will return to the ground first.
Answer:
False
Explanation:
The inner planets are called terrestrial planets due to the surfaces are solid (similar to Earth)-made up of heavy metals, either have no moons or few moons.
The outer planets are called Jovian planets or gas giants because they are encased in gas. They all have rings with plenty of moons.