Explanation:
a) <em>Fixed points</em> are the temperatures at which a thermometer is calibrated. They can refer either to the actual temperatures used for calibration, or the thermometer readings at those temperatures.
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b) <em>Fundamental interval</em> is the difference between the fixed points. As with fixed points, it can refer either to the difference in actual temperature, or the difference in the corresponding thermometer readings.
Answer:
20 J
Explanation:
Kinetic energy is given as half of the product of mass and the square of velocity of an object:
KE = 
where m = mass = 40 kg
v = velocity = 1 m/s
Hence, Mary's kinetic energy is:
KE = 
KE = 20 * 1 = 20 J
She has a kinetic energy of 20 J.
The diagram is missing; however, we know that the intensity of a sound wave is inversely proportional to the square of the distance from the source:

where I is the intensity and r is the distance from the source.
We can assume for instance that the initial distance from the source is r=1 m, so that we put

The intensity at r=3 m will be

Therefore, the sound intensity has decreased by a factor

.
The smallest level of organization in living things is the atom.
Next in line would be the cell, since a cell is made up of atoms working together. Next, cells working together would make up a tissue, and further, tissues working together would make up an organ.
1. Frequency: 
The energy given is the energy per mole of particles:

1 mole contains a number of Avogadro of particles,
, equal to
particles
So, by setting the following proportion, we can calculate the energy of a single photon:

This is the energy of a single photon; now we can calculate its frequency by using the formula:

where
is the Planck's constant
f is the photon frequency
Solving for f, we find

2. Wavelength: 
The wavelength of the photon is given by the equation:

where

is the speed of the photon (the speed of light). Substituting,
