Answer:
18 m
Explanation:
Given : vo = 0 m/s ; t = 3 s; a = 4 m/s^2 ; d = ? m ; average velocity = ? m/s ; fonal velocity = ? m/s
solving for the final velocity, v
v = a * t
v = 4 m/s^2 * 3 s
v = 12 m / s
Solving for the average velocity. avg v
avg v = (vo + v) / 2
avg v = (0 m / s + 12 m/s) / 2
avg v = 6 m / s
Solving for the distance traveled after 3 s
d = avg v * t
d = 6 m / s * 3 s
d = 18 meters
In the first 3s the car travels 18 meters.
Answer:
#_photons = 30 photons / s
Explanation:
Let's start by finding the energy of a photon of light, let's use the Planck relation
E = h f
the speed of light is related to wavelength and frequency
c = λ f
we substitute
E = h c /λ
E₀ = 6.63 10⁻³⁴ 3 10⁸/500 10⁻⁹
E₀ = 3.978 10⁻¹⁹ J
now let's use a direct proportion rule. If the energy of a photon is Eo, how many fornes has an energy E = 1.2 10⁻¹⁷ J in a second
#_photons = 1 photon (E / Eo)
#_photons = 1 1.2 10⁻¹⁷ /3.978 10⁻¹⁹
#_photons = 3.0 10¹
#_photons = 30 photons / s
Is that a question? .
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