Answer:
<em>Since I can see no choices, I answered it in my own understanding.</em>
Brian - amplitude and frequency
Marcia - amplitude and longitudinal wave
Explanation:
"Sound" and "sound waves" are essential part of a person's life. They can be used for<u> communicating</u> and <u>detecting some object</u>s.
Brian loves singing in the shower which means that he is using a greater amplitude. Amplitude refers to the<em> intensity of the sound </em>or the amount of energy that a sound carries. When one sings in the shower, the sound cannot travel very far. It bounces immediately back to the person singing thus, making the sound bigger. Brian is also using a <em>different range of </em><em>frequency</em><em> compared to his normal way of talking.</em> The frequency of a normal male voice is normally 85 to 180 Hz. A person singing may have a frequency as high as 1,500 Hz.
Marcia talks loudly on the phone. This means that she is also using a greater amplitude because the intensity of her voice is big. Since she is using the telephone, this means that her voice travels in a longitudinal wave through the telephone. This allows her voice to reach to the person on the other end of the line.
Answer:
the photons (quanta of light) collide with the electrons, these electrons have to overcome the threshold energy that is the energy of union with the metal, and the energy that remains is converted to kinetic energy.
K = E - Ф
Explanation:
The photoelectric effect is the emission of electrons from the surface of a metal.
This was correctly explained by Einstein, in his explanation the energy of the photons (quanta of light) collide with the electrons, these electrons have to overcome the threshold energy that is the energy of union with the metal, and the energy that remains is converted to kinetic energy.
E = hf
E = K + Ф
K = E - Ф
The energy of the photons is given by the Planck relation E = hf and according to Einstein the number of joints must be added
E = n hf
Therefore, depending on the value of this energy, the emitted electrons can have energy from zero onwards.
Choice A is correct.======Kinetic energy equation: KE = (1/2)(m)(v²)This tells us that KE is directly proportional to mass and the square of velocity. In other words, the more mass and more velocity an object has, the more kinetic energy.If an object is sitting at the top of a ramp, there is no velocity and therefore no kinetic energy. Choices B and D are wrong.A golf ball has more mass than a ping-pong ball, so a ping-pong ball would have less kinetic energy than a golf ball rolling off the end of a ramp. Choice C is wrong.Choice A is correct.
Explanation:
700N right
to get the net force
you gotta let one direction be the negative ( the smaller force)
so the total force towards the left is 100N ( 60 + 40= 100)
which is smaller than the right force which is 800 N so you let 100 N be negative
so without even calculating , you can know that it will be moving towards the right because right force > left force
your add both forces ( remember 100 N is negative)
so 800N + ( - 100N)
= 700N
towards the right
hope this helps
this is just one method that helped me understand
please mark it brainliest