The theodolite is a precision measuring device used to measure horizontal and vertical angles. It works with a combination of: (1) optical plummets, which is used to ensure that it is placed exactly vertical above; (2) internal spirit, which ensures that it is levelled to the horizon; and (3) graduated circles, one vertical and one horizontal, which is used to measure actual angles. The mounted telescope can swivel horizontally and vertically. If this is adjusted correctly, accurate measurements can be obtained.
Answer:

Explanation:
Given that,
An infrared telescope is tuned to detect infrared radiation with a frequency of 4.39 THz.
We know that,
1 THz = 10¹² Hz
So,
f = 4.39 × 10¹² Hz
We need to find the wavelength of the infrared radiation.
We know that,

So, the wavelength of the infrared radiation is
.
Answer:
The center of mass of the Earth-Moon system is 4.673 kilometers away from center of Earth.
Explanation:
Let suppose that planet and satellite can be treated as particles. The masses of Earth and Moon (
,
) are
and
, respectively. The distance between centers is 384,403 kilometers. The location of the center of mass can be found by using weighted averages:

If
and
, then:


The center of mass of the Earth-Moon system is 4.673 kilometers away from center of Earth.
Answer:
1327 kg
Explanation:
So the net force exerted on the wagon would be the sum of forces from 2 horses subtracted by friction force

This force results in an acceleration of a = 1.3 m/s2. We can use Newton's 2nd law to calculate the mass of the wagon


If you are talking about Isotopes then I believe it is the amount of atoms that have different amounts of neutrons ,but the same number of protons.