Answer:
Sound waves transfer energy by the motion of particles
Explanation: guessing lol
Plants, animals and bacteria
The second illustration is the best representation of the change in the movement of particles as the temperature of the water changes.
<u>Explanation:</u>
The second option perfectly represents the boiling of water. As when the temperature is increased, the water molecules gain energy to move faster, thus their kinetic energy of the atoms will be more. This will lead to more freely movement of all the atoms of the water.
And as boiling leads to transformation from liquid state to gaseous state, so the increase in the distance between atoms and molecules occurs in the gaseous state. Thus, the second illustration is best suitable for representing the boiling of water.
As on increasing temperature of the water, the distance between the molecules is increasing in the second illustration while the other illustration shows the decrease in the distance between the molecules. So, the second illustration is the best representation of the change in the movement of particles as the temperature of the water changes.
Molality of the solution is defined as the number of moles of a substance dissolved divided by the mass of the solvent:
Molality = number of moles / solvent mass
From the concentration of 39% (by mass) of HCl in water, we construct the following reasoning:
in 100 g solution we have 39 g hydrochloric acid (HCl)
number of moles = mass / molecular weight
number of moles of HCl = 39 / 36.5 = 1.07 moles
solvent (water) mass = solution mass - hydrochloric acid mass
solvent (water) mass = 100 - 39 = 61 g
Now we can determine the molality:
molality = 1.07 moles / 61 g = 0.018
Answer & Explanation:
In physics, a contact force is a force that acts at the point of contact between two objects, in contrast to body forces. Contact forces are described by Newton's laws of motion, as with all other forces in dynamics. Contact force is the force in which an object comes in contact with another object. Contact forces are also direct forces. Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball or pushing a desk across a room are some of the everyday examples where contact forces are at work. In the first case the force is continuously applied by the person on the car, while in the second case the force is delivered in a short impulse.
