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:

Explanation:
As we know that amplitude of forced oscillation is given as

here we know that natural frequency of the oscillation is given as

here mass of the object is given as



angular frequency of applied force is given as


now we have


Answer:
(a) B = 5.6 micro Tesla
Explanation:
Current in the wire, i = 140 A
distance, r = 5 m
The formula for the magnetic field at a distance r due to the current carrying wire


B = 5.6 x 10^-6 Tesla
B = 5.6 micro Tesla
(b) As the magnetic field of earth at this site is 20 micro tesla so the magnetic field due to current carrying wire interfere the magnetic compass.
Answer:
There are six kinds of forces that act on objects when they come into contact with one another: Normal force, applied force, frictional force, tension force, spring force and resisting force. These forces make objects change their motion or movement , the act of going from one place to another.
r₁ = distance of the point from the source = 43 km = 43000 m
I₁ = intensity of earthquake wave at distance "r₁" = 2.5 x 10⁶ W/m²
r₂ = distance of the point from the source = 1.5 km = 1500 m
I₂ = intensity of earthquake wave at distance "r₂" = ?
we know that , for a constant power , the intensity of wave is inversely proportional to the distance from the source .
I α 1/r² where I = intensity of wave , r = distance from source
hence we can write
I₁/I₂ = r₂²/r₁²
inserting the values
(2.5 x 10⁶) /I₂ = (1500/43000)²
I₂ = 2.1 x 10⁹ W/m²