We must use two formulas of energy first how energy is related to wavelength:
Such that , c is the speed of light in a vacuum and h is Plank's constant.
And the second equation is how energy relates to voltage:
Such that q is the charge of the particle (in this case the electron) and V is voltage. By substituting the second equation into the first we have:
We know that:
And so:
Answer:
The potential energy of a 2 kg mass at a height of 40 meters is 784 J
Explanation:
Potential energy is that energy that a body possesses due to the height at which it is located and whose unit of measurement of the International System of Units is the joule (J).
The potential energy of a body is the result of multiplying its mass by its height and by gravity:
Ep=m*g*h
Potential energy Ep, is measured in joules (J), mass m is measured in kilograms (kg), gravity, g, in meters / second-squared (), and height, h , in meters (m).
In this case:
- Ep=?
- m= 2 kg
- g= 9.8
- h= 40 m
Replacing:
Ep= 2 kg* 9.8 * 40 m
Solving:
Ep= 784 J
<u><em>The potential energy of a 2 kg mass at a height of 40 meters is 784 J</em></u>
Answer:
a. 3/4λ
d. 1/4λ
Explanation:
When the wavelength of the sound waves is λ and the two waves are having same frequency the waves are said to be out of phase if their phase difference is in the multiples of or 180°.
When the two waves are out of phase then their opposite maxima coincide at the same time resulting in the minimum amplitude of the resulting wave throughout.
- As we observe from the schematic that the a wave has sinusoidal pattern of variation and we get a maxima after each of the distance.
- Here we have two speakers out of phase therefore on shifting one of the speakers by the odd multiples of we have the maxima or the extreme amplitudes.
So, we must place the microphone at 3/4λ and 1/4λ to pickup the loudest sound.
Answer:
F1 is equal to F2
Explanation:
Here
F1 is the gravitational force exerted by the earth on the satellite.
F2 is the gravitational force exerted by the satellite on the earth.
Now these two forces are equal but opposite in nature. This is given by the Third law of motion by Newton. According to this law, when there is force exerted between two objects, one force is balanced the other force which is equal in magnitude and opposite in nature.
Thus the gravitational force of the earth exerted on the satellite is equal to the force exerted by the satellite on the earth.
Hence F1 = F2.
B because under the blade it curves