Answer:
Correct answer: (a) Ekmax = 1.3 · 10⁻¹⁹ J, (b) ε = 5 eV, (c) f = 1.21 · 10¹⁵ Hz
Explanation:
Given:
photon energy ε = 8 · 10⁻¹⁹ J
work function for metal Wf = 6.7 · 10⁻¹⁹ J
(a) Ekmax = ?
The Einstein equation for photo effect is:
ε = Wf + Ekmax ⇒ Ekmax = ε - Wf
Ekmax = 8 · 10⁻¹⁹ - 6.7 · 10⁻¹⁹ = 1.3 · 10⁻¹⁹ J
Ekmax = 1.3 · 10⁻¹⁹ J
(b) ε = ? eV
the relationship between 1 eV and 1 J is:
1 eV = 1.6 · 10⁻¹⁹ J
so the energy of one photon in eV equals:
ε = 8 · 10⁻¹⁹ J = 8 · 10⁻¹⁹ / 1.6 · 10⁻¹⁹ eV = 5 eV
ε = 5 eV
(c) f = ?
the energy of a single photon is calculated according to the formula:
ε = h · f
where is:
h = 6.62 · 10⁻³⁴ J s plank constant
and f frequency of each photon (electromagnetic radiation)
f = ε / h = 8 · 10⁻¹⁹ J / 6.62 · 10⁻³⁴ J s = 1.21 · 10¹⁵ s⁻¹ = 1.21 · 10¹⁵ Hz
f = 1.21 · 10¹⁵ Hz
God is with you!!!
Answer:
80km/hr
Explanation:
Hope this helps! :>
p.s. is this right? i'm not 100% sure...:I
Answer:
The angle of elevation of the Sun = 41.8°
Explanation:
Let the angle of elevation of the sun be θ
Using trigonometric relations,
Tan θ = opp/adj
opp = the height of the Washington Tower = 555 ft
adj = the length of the shadow = 620 ft
Tan θ = (555/620) = 0.8952
θ = Tan⁻¹ (0.8952) = 41.8°
Hence, the angle of elevation of the Sun = 41.8°
The choice that is most likely end for a star that formed from an extremely large nebula would be a black hole. Gravity pulls so much in a black hole that no light exists.
