The Doppler effect is the change in sound or light that occurs whenever there is motion between the source and its observer. The siren of the fire engine has a lower pitch as it moves away because the waves are now spread out causing a lower frequency and a lower pitch. High-frequency sound waves have a higher pitch and higher energy than low-frequency waves.
I changed my undershorts. The elastic on the old ones I put on that day was deteriorated, and it completely failed when I dripped lab coffee on it, causing falldown.
Answer:
Mass of star is 
kg.
Explanation:
The cube of orbital radius is equal to the square of its orbital time period is known as Kepler's law.
.....(1)
Here T is time period, r is orbital radius, G is universal gravitational constant and M is the mass of the star.
According to the problem,
Time period, T = 109 days = 109 x 24 x 60 x 60 s = 9.41 x 10⁶ s
Orbital radius, r = 18 AU = 18 x 1.496 x 10¹¹ m = 2.70 x 10¹² m
Gravitational constant, G = 6.67 x 10⁻¹¹ m³ kg⁻¹ s⁻²
Substitute these values in equation (1).
M = kg
The maximum compression of the spring is 0.6 m.
<h3>
Spring constant</h3>
The spring constant of the spring is calculated as follows;
F = kx
k = F/x
k = (5)/(0.1)
k = 50 N/m
<h3>Maximum compression of the spring</h3>
The maximum compression of the spring is calculated as follows;
U = K.E
¹/₂kx² = ¹/₂mv²
x² = (mv²)/(k)
x = √(mv²)/(k)
x = √(4.5 x 2²)/(50)
x = 0.6 m
Thus, the maximum compression of the spring is 0.6 m.
Learn more about spring constant here: brainly.com/question/1968517
