Answer:
k = 1400.4 N / m
Explanation:
When the springs are oscillating a simple harmonic motion is created where the angular velocity is
w² = k / m
w = 
where angular velocity, frequency and period are related
w = 2π f = 2π / T
we substitute
2π / T = \sqrt{ \frac{k}{m} }
T² = 4π² 
k = π² 
in this case the period is T = 1.14s, the combined mass of the children is
m = 92.2 kg and the constant of the two springs is
k = 4π² 92.2 / 1.14²
k = 2800.8 N / m
to find the constant of each spring let's use the equilibrium condition
F₁ + F₂ - W = 0
k x + k x = W
indicate that the compression of the two springs is the same, so we could replace these subtraction by another with an equivalent cosecant
(k + k) x = W
2k x = W
k_eq = 2k
k = k_eq / 2
k = 2800.8 / 2
k = 1400.4 N / m
Having in mind that a spontaneous process is capable of proceeding in a given direction without needing to be driven by an outside source of energy, then it must occur naturaly. This is actually spontaneous. Also take into account that in order to define a spontaneous pattern we need to state no work performed on the system or on the surroundings.
Answer:
It will float
Explanation:
its density is lower than density of water
Its density is 670 / 782 = 0.856 kg/m³
White dwarfs
<u>Explanation:</u>
Hertzsprung-Russel graph is a 2-dimensional graph, plotting star’s luminosity against temperature they emit.
White dwarfs are the star exhibiting high temperatures and low luminosities. These stars are extremely dense and mass comparable to that of the sun.
The main cause of low luminosities in the absence of fusion reaction inside the core of the star. Faint luminosity is provided by the thermal energy of the star. They are considered to be in the final stage of evolution having masses in the range of 10 solar mass (hence not enough to form a star)
Answer:
The slower the train is moving, the less are the changes of the magnetic flux, thus the eddy currents become weaker.
Explanation:
A magnetic brakes is not a very efficient way of braking when a train is moving slowly because at low speeds, the changes in the magnetic flux are very less and so it causes the eddy current to become weaker.
Let us find the drag force which is proportional to the velocity of two conducting plates.
The EMF that is induced in the eddy currents are : 
The force which is due to the induced magnetic field is, 
Therefore, 
Here, force is directly proportional to the velocity of the two conducting plates.
Therefore, we can say that when the speed of the train is low, the magnetic flux changes are less and thus the eddy currents are weaker.
