Explanation:
The scanner records the time from when a ultrasound wave is emitted to when its reflection is received. A technician calculates the depth of the reflection using the equation as :

The distance covered by ultrasonic wave when it was emitted and gets reflected is 2d. Speed is given by :

d is distance and t is time
Here, d = 2d
So, the factor of (1/2) is used because the distance covered by the wave is 2 times when it was emitted and received.
4 km/hr. There are four quarters in an hour, so just divide 16 by 4 and you get 4. It is directly proportional.
The electron in a ground-state H atom absorbs a photon of wavelength 97. 25 nm. Energy level till where the electron move is 4
Rydberg's equation is formula which signifies relation of wavelength of incident photon and the energy level.
Rydberg's equation is used to find out the relation between the wavelength and the Energy Levels:
1/λ = RZ² (1/n₁² - 1/n₂²)
where, λ is wavelength = 97.25 nm
R is the Rydberg constant = 1.0967 × 10⁷ m
n₁ is the initial energy level i.e. the Ground state, n₁ = 1
n₂ is the higher energy level
On substitution of the above value:
1/97.25 × 10⁻⁹ = 1.0967 × 10⁷ ( 1 - 1/n₂²)
On solving,
⇒ n₂ = 4
Hence, the higher energy level is 4
Learn more about Energy Level here, brainly.com/question/17396431
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how does the electric force between two charged particles change if the distance between them is increased by a factor of 3?
a. it is reduced by a factor of 3
Answer:

The splitting up of light into its constituent colours while passing from one medium to the other is called dispersion.