1. An object in free fall will have an initial velocity equal to zero when: a. It is thrown vertically down
1 answer:
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Answer:
4kg
Explanation:
Given parameters:
Kinetic energy = 1.6J
Velocity = 0.2m/s
Unknown:
Mass of the body = ?
Solution:
The kinetic energy of a body is the energy due to the motion of the body.
It is mathematically expressed as;
Kinetic energy = m v²
m is the mass
v is the velocity
1.6 = x 0.2 x v²
1.6 = 0.1v²
v² = 16
v = 4kg
Answer:
a) v = 4.37 10⁶ m / s, speed is much less than c
b) v = 2.01 10⁸ m / s, this value is 67% of the speed of light, , for which relativistic corrections should be used
Explanation:
The bohr model for the hydrogen atom and dendroids is a classical model with a quantization of the angular momentum
let's start by using Newton's second law with the electric force
F = m a
Coulomb's law electric force
F =
in this case in an atom the number of protons is equal to the atomic number and there is only one electron
q₁ = Ze
q₂ = e
acceleration is centripetal
a = v² / r
we substitute
v² =
quantization is imposed without justification in this model,
L = p x r = n
\hbar= h /2π
if we consider circular orbits, the speed and position are perpendicular
m v r = n \hbar
r =
we substitute
v² =
v =
let's apply this equation
\hbar= h / 2π
\hbar= 6.626 10-34 / 2π
\hbar= 1.05456 10⁻³⁴ J s
a) He1 ion, the atomic number of helium is 2
v =
v =4.3695 10⁶ / n m / s
the ground state occurs for N = 1
v = 4.37 10⁶ m / s
the relationship of this value to the speed of light is
v / c = 4.37 10⁶/3 10⁸
v / c = 1.46 10⁻²
speed is much less than c
b) the uranium ion with atomic number Z = 92
v =
v = 2.01 10⁸ m / s
v/c =
v/c = 0.67
this value is 67% of the speed of light, for atoms with a higher atomic number the effects are increasingly important, for which relativistic corrections should be used