Answer:
I think it's the most important part in this
Answer: B. II and III only
Explanation:
Let’s begin by explianing what energy is: the ability of matter to produce work in the form of movement, light, heat, among others. In this sense, there are several types of energy, but we will talk especifically in this case about <u>kinetic energy</u> and <u>potential energy</u>.
<u>Kinetic energy </u>is the energy an object or body has due to its movement and depends on the mass and velocity of the object or body.
To understande it better: If an object is at rest, its velocity is null and it does not have kinetic energy, however, if the object is moving, then it has kinetic energy.
On the other hand, <u>Potential energy</u> is known as <em>“stored energy”</em> that has the potential to be converted into energy of motion (kinetic energy) or another type of energy (thermal energy, for example). In addition, this energy is related to the work done when a certain force moves an object or body from its natural resting state along a distance to a new position.
So, according to this, Kinetic energy can be transformed into potential energy and Potential energy can be transformed into kinetic energy or any other type of energy. Hence, options II and III are correct.
Answer: I don't know this one but I'm just came here for points
Explanation:
Answer:
B) Power
Explanation:
The power is defined by the following equation:
P = W / t
where:
W = work = Force * Distance = [Newton] * [meter]
t = time = seconds
The units for work are give en Newton per second, which is equal to Joules
And for power the unit used commonly is Watts, therefore:
Watts = (Joule/second)
Answer:
![0.293I_0](https://tex.z-dn.net/?f=0.293I_0)
Explanation:
When the unpolarized light passes through the first polarizer, only the component of the light parallel to the axis of the polarizer passes through.
Therefore, after the first polarizer, the intensity of light passing through it is halved, so the intensity after the first polarizer is:
![I_1=\frac{I_0}{2}](https://tex.z-dn.net/?f=I_1%3D%5Cfrac%7BI_0%7D%7B2%7D)
Then, the light passes through the second polarizer. In this case, the intensity of the light passing through the 2nd polarizer is given by Malus' law:
![I_2=I_1 cos^2 \theta](https://tex.z-dn.net/?f=I_2%3DI_1%20cos%5E2%20%5Ctheta)
where
is the angle between the axes of the two polarizer
Here we have
![\theta=40^{\circ}](https://tex.z-dn.net/?f=%5Ctheta%3D40%5E%7B%5Ccirc%7D)
So the intensity after the 2nd polarizer is
![I_2=I_1 (cos 40^{\circ})^2=0.587I_1](https://tex.z-dn.net/?f=I_2%3DI_1%20%28cos%2040%5E%7B%5Ccirc%7D%29%5E2%3D0.587I_1)
And substituting the expression for I1, we find:
![I_2=0.587 (\frac{I_0}{2})=0.293I_0](https://tex.z-dn.net/?f=I_2%3D0.587%20%28%5Cfrac%7BI_0%7D%7B2%7D%29%3D0.293I_0)