Answer:
Height from ground is 8 m where string will break
Explanation:
Let the string makes some angle with the vertical after some instant of time
So here we have


now by energy conservation we have




For string break down we have


Now height from the ground is given as



Answer:
Pascal's law (also Pascal's principle or the principle of transmission of fluid-pressure) is a principle in fluid mechanics given by Blaise Pascal that states that a pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.
So the best conductor for electricity is silver.
However because silver is so expensive we use copper which is the next best conductor
The rays of light coming from the Sun are parallel to each other, so when they are reflected by the concave piece of glass (which acts as a concave mirror) they converge into the focus of the mirror, which is

The radius of curvature of a concave mirror is twice its focal length, so in this case it is:
1) The correct answer is
<span>C) The particles are not able to move out of their positions relative to one another, but do have small vibrational movements.
In solids, in fact, particles are bound together so they cannot move freely. However, they can move around their fixed position with small vibrational movements, whose intensity depends on the temperature of the substance (the higher the temperature, the more intense the vibrations). For this reason, we say that matter moves also in solid state.
2) The correct answer is
</span><span>A) increase the concentration of both solutions
In fact, when we increase the concentration of both solutions, we increase the number of particles that react in both solutions; as a result, the speed of the reaction will increase.
3) The correct answer is
</span><span>C) gas → liquid → solid
In gases, in fact, particles are basically free to move, so the intermolecular forces of attraction are almost negligible. In liquids, particles are still able to move, however the intermolecular forces of attraction are stronger than in gases. Finally, in solids, particles are bound together, so they are not free to move and the intermolecular forces of attraction are very strong. </span>