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.
Answer: The speed will be 30 m/s .
Explanation:
Given: Initial velocity of the car: u = 0 m/s
Constant Acceleration: a = 5 m/s²
Time: t= 6 seconds
To find: Final velocity(v)
Formula: v = u+at
Substitute values in the formula, we get
v= 0+(5)(6) m/s
⇒ v= 30 m/s
i.e. Final velocity = 30 m/s
Hence, the speed will be 30 m/s .
Answer:
C. scientists possess varied talents and interests.
Explanation:
The above passage suggests clearly that often times, scientists possess varied talents and interests.
Cases were made of Abū Rayhān al-Bīrūnī and Robert Hooke. Both were scientists and had the same time had interests in other disciplines.
- Abū Rayhān al-Bīrūnī, a Persian made scientific contribution to the studies of heat, more so, his interest in cultures lucidly made him an erudite and foremost founding father of anthropology. Physics/mathematics and Anthropology are different fields with varied interests.
- Robert Hooke, was interested in physics. Besides this, he was skilled architect and surveyor. Physics and architecture/surveying are different fields. They are varied and dissimilar in nature.
Therefore, we can argue that the tone set by the author conveys a clear focal point that often times, scientists possess varied talents and interests.
The answer is crystalline solid. Crystalline solids have a regular arrangement of particles, because of that, they possess definite geometry.
This means that if you take a look at the crystal under the microscope you would notice that there is a pattern that constantly repeats. This pattern is called a unit cell, and crystal is made up of stacked unit cells.
Answer:
the tension in the part of the cord attached to the textbook is 7.4989 N
Explanation:
Given the data in the question;
As illustrated in the image below;
first we determine the value of the acceleration,
along vertical direction; we use the second equation of motion;
y = ut + 
a
t²
we substitute;
0 m/s for u, 1.29 m for y, 0.850 s for t,
1.29 = 0×0.850 + ×a×(0.850)²
1.29 = 0.36125a
a = 1.29 / 0.36125
a = 3.5709 m/s²
Now when the text book is moving with acceleration , the dynamic equation will be;
T₁ = m₁a
where m₁ is the mass of the text book ( 2.10 kg )
a is the vertical acceleration ( 3.5709 m/s² )
so we substitute
T₁ = 2.10 × 3.5709
T₁ = 7.4989 N
Therefore, the tension in the part of the cord attached to the textbook is 7.4989 N
