Answer:
if i'm not mistaken that's either a plug in cord for a certain device, or what i am assuming to be a usb software cord.
Explanation:
Answer:
0.79 s
Explanation:
We have to calculate the employee acceleration, in order to know the minimum time. According to Newton's second law:
The frictional force is maximum since the employee has to apply a maximum force to spend the minimum time. In y axis the employee's acceleration is zero, so the net force is zero. Recall that 
Now, we find the acceleration:
Finally, using an uniformly accelerated motion formula, we can calculate the minimum time. The employee starts at rest, thus his initial speed is zero:
Answer:
- The limitation of the maximum number of electrons in a given energy level can be used to account for the periodic recurrence of properties as the number of electrons increases.
Explanation:
First - Scientists have not yet determined exactly why electrons do not collapse into the nucleus. FALSE: Scientists do know why electrons do not collapse. Since the beginins of quantum mechanics it's known that the energy at small scales is quantized, that means there only can be certain values meaning that the energy do not change continously. In the case of the electron, it can only have certain levels of energy, that means they do not radiate continously as the go arround the atom, instead it is only allowed to have a certain amount of energy in a given state therefore it can not lose energy continously collapsing into the nucleus.
Second - Electrons cannot be located between levels except when they are in the process of moving. FALSE: We can not say that a electron moves between energy levels, it only can exist in any of the levels, but never in between. Also, the electron in any of its possible energy lavels can not be located with complete certainty due to the uncertainty principle.
Fourth - Electrons have any random energy. FALSE: as exposed above the electrons can only have certain cuantized energy levels acordinly to the rules of quantum physics
Fifth - Electrons can be found between energy levels. FALSE: Like said before we can not say that a electron exists between energy levels, it only can exist in any of the allowed levels, but never in between.
Thirth (correct one) : - The limitation of the maximum number of electrons in a given energy level can be used to account for the periodic recurrence of properties as the number of electrons increases. TRUE: the maximum number of electrons allowed in a given energy level directly determines the tipe of bond an atom can made with another (this due to the number of electrons in the higest energy level), so for example the elements in the left of a given row of the periodic table tend to have ionic bonds, but in the other hand the elements on right side tend form more covalent bonds. And this characteristic directly correllate with diferent properties of the elements.
Answer:
Sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear.
Answer:
Explanation:
Distance travelled by wave = 8 x 2 = 16 m
Time taken = 4 s
velocity of pulse wave = distance / time
= 16 m / 4 s
= 4 m/s
