Answer:
λ = 5.4196 10⁻⁷m, λ = 541.96 nm this is green ligh
Explanation:
The photoelectric effect was explained by Eintein assuming that the light was made up of particles called photons and these collided with the electrons taking them out of the material.
K = h f -Ф
where K is the kinetic energy of the ejected electrons, hf is the energy of the light quanta and fi is the work function of the material.
The speed of light is related to wavelength and frequency
c = λ / f
f = c /λ
we substitute
K = h c / λ - Φ
for the case that they ask us the kinetic energy of the electons is zero (K = 0)
h c / λ = Ф
λ = h c / Ф
we calculate
λ = 6.63 10⁻³⁴ 3 10⁸ / 3.67 10⁻¹⁸
λ = 5.4196 10⁻⁷m
let's take nm
lam = 541.96 nm
this is green light
Able to be hammered or pressed permanently out of shape without breaking or cracking.
Answer:
D. Because mass and energy are both conserved, the total amounts of mass and energy are the same before and after impact.
Explanation:
As we know that, the energy in motion is Kinetic Energy mathematically given as:
<u>Now, according to the law of conservation of energy:</u>
where:
mass of racquet and ball respectively and 
are their respective initial velocities.
are the respective final velocities.
<u>Also the law of conservation of momentum is applicable in this case:</u>
In this case the velocity of the lighter mass will get increases in the final condition.
