Answer:
A. The model was the result of hundreds of years of experiments.
Explanation:
Since it is not possible to visualize an atom in isolation, scientists have spent hundreds of years experimenting and creating atomic models, that is, images that serve to explain the constitution, properties and behavior of atoms.
The earliest who imagined the existence of the atoms were the Greek philosophers Leucippus and Democritus in about 450 BCE. According to them, everything would be formed by tiny indivisible particles. Hence the origin of the name "atom", which comes from the Greek a (no) and tome (parts).
But in the nineteenth century, some scientists began to conduct experimental tests increasingly accurate thanks to technological advances. Not only was it discovered that everything was actually made up of tiny particles, but it was also possible to understand more and more about the atomic structure.
Scientists used the information discovered by other scholars to develop the atomic model. In this way, the discoveries of one scientist were replaced by those of others. The concepts that were correct remained, but those that proved to be non-real were now abandoned. Thus, new atomic models were created. This series of discoveries of the atomic structure until arriving at the accepted models today was known like the evolution of the atomic model.
Explanation:
Given that,
Mass, m = 0.08 kg
Radius of the path, r = 2.7 cm = 0.027 m
The linear acceleration of a yo-yo, a = 5.7 m/s²
We need to find the tension magnitude in the string and the angular acceleration magnitude of the yo‑yo.
(a) Tension :
The net force acting on the string is :
ma=mg-T
T=m(g-a)
Putting all the values,
T = 0.08(9.8-5.7)
= 0.328 N
(b) Angular acceleration,
The relation between the angular and linear acceleration is given by :
(c) Moment of inertia :
The net torque acting on it is, 
, I is the moment of inertia
Also, 
So,
Hence, this is the required solution.
Answer:
λ = 6.602 x 10^(-7) m
Explanation:
In a double-slit interference experiment, the distance y of the maximum of order m from the center of the observed interference pattern on the screen is given as ;
y = mλD/d
Where;
D is the distance of the screen from the slits = 6.2 m
d is the distance between the two slits = 0.046 mm = 0.046 x 10^(-3) m
The fringes on the screen are 8.9 cm = 0.089 m apart from each other, this means that the first maximum (m=1) is located at y = 0.089 m from the center of the pattern.
Therefore, from the previous formula we can find the wavelength of the light:
y = mλD/d
So, λ = dy/mD
Thus,
λ = (0.046 x 10^(-3) x 0.089)/(1 x 6.2)
λ = 6.602 x 10^(-7) m
Eugene Cernan was not the last, but he was the most recent.
