The Huns' invasion of Europe caused a mass migration driving Germanic tribes of Northern Europe to the borders of the Roman Empire which led to the Barbarian attacks on Rome.
Answer:
A. It is zero.
Explanation:
D Later in the day, more power is developed in lifting each box. 12 A manometer is used to indicate the pressure in a steel vessel, as shown in the diagram. What value does the liquid manometer give for the pressure in the vessel? It is zero
Answer:
The orbital speed of this second satellite is 5195.16 m/s.
Explanation:
Given that,
Orbital radius of first satellite 
Orbital radius of second satellite 
Mass of first satellite 
Mass of second satellite 
Orbital speed of first satellite = 4800 m/s
We need to calculate the orbital speed of this second satellite
Using formula of orbital speed

From this relation,

Now, 

Put the value into the formula


Hence, The orbital speed of this second satellite is 5195.16 m/s.
The particles of the liquid inside a thermometer speed up and spread apart when the thermometer is heated. In short, the particles expand from one another when they're heated, and become condensed and compact when chilled.
Answer:
The frequency of sound heard by the boy is 1181 Hz.
Explanation:
Given that,
Frequency of sound from alarm 
Speed = -8.25 m/s
Negative sign show the boy riding away from the car
Speed of sound = 343
We need to calculate the heard frequency
Using formula of frequency

Where,
= frequency of source
= speed of observer
= speed of source
= speed of sound
Put the value into the formula

here, source is at rest


Hence, The frequency of sound heard by the boy is 1181 Hz.