Answer:
The amount of work done required to stretch spring by additional 4 cm is 64 J.
Explanation:
The energy used for stretching spring is given by the relation :
.......(1)
Here k is spring constant and x is the displacement of spring from its equilibrium position.
For stretch spring by 2.0 cm or 0.02 m, we need 8.0 J of energy. Hence, substitute the suitable values in equation (1).

k = 4 x 10⁴ N/m
Energy needed to stretch a spring by 6.0 cm can be determine by the equation (1).
Substitute 0.06 m for x and 4 x 10⁴ N/m for k in equation (1).

E = 72 J
But we already have 8.0 J. So, the extra energy needed to stretch spring by additional 4 cm is :
E = ( 72 - 8 ) J = 64 J
The amplitude of a sound<span> wave </span>determines<span> its </span>loudness<span> or volume. A larger amplitude means a louder </span>sound<span>, and a smaller amplitude means a softer </span><span>sound</span>
Answer:
Characteristic numbers are dimensionless numbers used in fluid dynamics to describe a character of the flow. To compare a real situation with a small-scale model it is necessary to keep the important characteristic numbers the same. Names of these numbers were standardized in ISO 31, part 12.
Explanation:
Magnetic domain is defined as a group of atoms with magnetic fields.
A piece of iron can only become a magnet when the magnetic domain aligns.
Since we have an unmagnetized piece of iron, this means that its domain is not aligned. However, this does not mean that the domain does not exist.
Based on the above, the best choice would be:
There arr domains, but domains are oriented randomly.
Hope this helps :)