Answer:
Because they want attention
This is just testing your ability to recall that kinetic energy is given by:
<span>k.e. = ½mv² </span>
<span>where m is the mass and v is the velocity of the particle. </span>
<span>The frequency of the light is redundant information. </span>
<span>Here, you are given m = 9.1 * 10^-31 kg and v = 7.00 * 10^5 m/s. </span>
<span>Just plug in the values: </span>
<span>k.e. = ½ * 9.1 * 10^-31 * (7.00 * 10^5)² </span>
<span>k.e. = 2.23 * 10^-19 J
so it will be d:2.2*10^-19 J</span>
Answer:
Protons, Electrons, and Neutrons are the 3 primary particles in an atom.
Protons - (+1)
Electrons - (-1)
Neutrons - (0)
<h3>Your answer would be C</h3>
The discovery of gallium was significant as it confirmed Mendeleev’s predictions and showed the usefulness of his table.
Answer: Option First
<u>Explanation:
</u>
In 1871, Mendeleev prepared a periodic table of all known elements to study their properties. While making the table, he left some places in the table for elements that were yet to be discovered. One of the elements was eka-aluminium.
In 1875, a French scientist Paul Emile Francois Lecoq de Boisbaudran discovered a new element spectroscopically in the course of examining zinc blende. This newly discovered element showed the same properties as predicted by Mendeleev for the eka-aluminium with an atomic weight 69.
Later, the specific gravity of the element was also found to be the same as predicted by Mendeleev i.e. 5.9. After this, Lepoq named the element as Gallium, which confirmed Mendeleev’s predictions and made his periodic table worthier.
Answer:
The frequency will decrease by a factor of square root of 2 (<em>ω = √(2 (g / L))</em>.
Explanation:
A simple pendulum consists of a mass m hanging from a string of length L and fixed at a pivot point P. When displaced to an initial angle and released, the pendulum will swing back and forth with periodic motion. By applying Newton's second law for rotational systems, the equation of motion for the pendulum may be obtained
τ = I α ⇒ - mg sin(θ) L = mL² (d²θ/dt²)
where
- τ is torque
- I is the moment of inertia
- α is the angular frequency
- g is the acceleration due to gravity
- L is the length of the string
- m is the mass of the ball
The above expression can be rearranged as
(d²θ/dt²) + g / L (sin(θ)) = 0
If the amplitude of angular displacement is small enough that the small angle approximation () holds true, then the equation of motion reduces to the equation of simple harmonic motion
(d²θ/dt²) + g / L (θ) = 0
The simple harmonic solution is
θ(t) = θ₀ cos(ωt + Ф)
where
- ω is the frequency of the pendulum
- Ф is the phase angle
The frequency is expressed as
ω = √(g / L)
If the pendulum is pulled from equilibrium by 2 times theta, The simple harmonic solution will be
θ(t) = θ₀ cos(2 ωt + Ф)
and therefore,<em> the frequency will be</em>
<em>ω = √(2 (g / L))</em>