Answer:
diffraction
Explanation:
diffraction occurs when light passes sharp edges or goes through narrow slits the rays are deflected and produce fringes of light and dark bands
Answer:
The frequency increases by a factor of 3.
Explanation:
The relation between speed, wavelength and frequency of a wave is given by :
or
A wave travels at a constant speed. If the wavelength is reduced by a factor of 3, it would mean that the frequency increases by a factor of 3 because there is an inverse relationship between wavelength and frequency.
The velocity of the ferry relative to the current is 4.5 m/s.
<h3>Relative velocity</h3>
- Relative velocity is the velocity of a body as observed from the reference point of another body either stationary or in motion.
Since the river is flowing parallel to the shore and the ferry is moving perpendicular to the shore, their velocities are at right angles to each other.
The two velocities form a right angled-triangle of sides 2, 4 and a hypotenuse which gives the relative velocity of the ferry to the current.
Using Pythagoras rule:
- Let c be the hypotenuse
- a = velocity of the ferry, and
- b = the velocity of the current, and
c² = 4² + 2²
c² = 16 + 4
c = 20
c = √20
c = 4.47 m/s
c ≈ 4.5 m/s
Therefore, the velocity of the ferry relative to the current is 4.5 m/s.
Learn more about relative velocity and Pythagoras rule at: brainly.com/question/25617868
<h2>
Answer: The Systeme international (International System of Units
)</h2>
The International System of Units (SI) is used in almost every country in the world (<em>except Burma, Liberia and the United States</em>).
This system was created in 1960 by the 11th General Conference of Weights and Measures in France and is made up of seven basic units:
-Ampere (electric current)
-Kelvin (temperature)
-Second (time)
-Meter (length)
-Kilogram (mass)
-Candela (luminous intensity)
-Mol (amount of substance) *added to the system in 1971
Plus an unlimited number of derived units from the main ones.
