All the radiation from stars is the result of nuclear fusion in their cores.
First, when the student added the layers of wax over each other, this became a representation of sedimentary rocks.
Then the student folded his/her palm and squeezed the layers of wax. This means that the student applied heat and pressure on the wax (sedimentary rocks)
Referring to the diagram below which represents the rock cycle, we will find that applying heat and pressure on sedimentary rocks would convert these rocks into metamorphic rocks.
Based on the above, the best choice would be:<span>d. Heat and pressure can change sedimentary rocks into metamorphic rocks.</span>
Answer:
4:28
Explanation:
4:28am
a 12 hour clock continues going up after 12 (1:00pm=13:00). minutes stay the same. 12:00pm=00:00. this shows 4:28am, so you count 4 after 00:00.
Answer:
- Direct current is a current in which electrons flow in one direction only
- Alternating current is a current in which the direction of the electron flow reverses periodically - so, half a cycle forward, half a cycle backward
There are several advantages of using alternating currents for the transmission of electricity across a country, over large distances. The main advantages are:
- The voltage of alternating currents can be easily increased/decreased by using transformers. For instance, a transformer is used at the beginning of the transmission line to increase the voltage (electricity is transmitted at high voltage in order to reduce dissipated power), and then another transformer is used before the electricity enters the houses, in order to decrease the voltage. Transformers only work with alternating currents.
- It is easy to interrupt the flow of an alternating current, because its value naturally becomes zero every half a cycle, so this is useful in case the current must be interrupted.
Answer:
Therefore the correct statement is B.
Explanation:
In the interference and diffraction phenomena, the natural wave of electromagnetic radiation must be taken into account, the wave front that advances towards the slit can be considered as when it reaches it behaves like a series of wave emitters, each slightly out of phase from the previous one, following the Huygens principle that states that each point is compiled as a source of secondary waves.
The sum of all these waves results in the diffraction curve of the slit that has the shape
I = Io sin² θ /θ²
Where the angle is a function of the wavelength and the width of the slit.
From the above, the interference phenomenon can be treated as the sum of two diffraction phenomena displaced a distance equal to the separation of the slits (d)
Therefore the correct statement is B
