Answer:
ΔE = 1.031 eV
Explanation:
For this exercise let's calculate the energy of the photons using Planck's equation
E = h f
wavelength and frequency are related
c = λ f
f = c /λ
let's substitute
E = h c /λ
let's calculate
E = 6.63 10⁻³⁴ 3 10⁸/1064 10⁻⁹
E = 1.869 10⁻¹⁹ J
let's reduce to eV
E = 1.869 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
E = 1.168 eV
therefore the electron affinity is
ΔE = E - 0.137
ΔE = 1.168 - 0.137
ΔE = 1.031 eV
Any sample of an <em>ELEMENT</em> is made of only one type of atom.
Here are some elements:
-- Hydrogen, Helium, Neon
-- Carbon (lead in a pencil, also diamonds)
-- Oxygen, Nitrogen, Argon (All mixed together in air, but not hooked up with other atoms)
Other elements you may have heard of:
-- Silver, Gold, Copper, Iron, Lead, Aluminum, Silicon, Chlorine, Calcium, Titanium, Nickel, Tin, Platinum, Mercury, Radium, Uranium
Answer:
1.23 m/s
Explanation:
The kinetic energy of the sprinter is:
KE = 0.5 * m(s) * v²
KE = 0.5 * 77 * 7.5²
KE = 2165.63 J
If the KE of the sprinter and the KE of the elephant are equal, hence:
2165.63 = 0.5 * m(e) * v²
2165.63 = 0.5 * 2850 * v²
=> v² = 1.52
v = √(1.52)
v = 1.23 m/s
Answer: Yes it possible for a system to have negative potential energy, since the choice of the zero of potential energy is arbitrary.
Explanation:
Potential energy is defined as the energy present in an object due to its position.
Mathematically, P.E = mgh
A potential energy can be negative also. This is because zero potential energy is arbitrary. For example, at the top of a building the choice of potential energy can be zero.
Therefore, the potential energy below the building will be negative.