During Physical Change there would be a re-arrangements of atoms or molecules, changes of the arrangement may be change in the distance between atoms or molecules, change in the crystal form, .....etc
for example: water when heated it undergoes a Physical Change and turn into vapor, this means the heat cause the distance between water molecules to increase, so it transferred from the liquid form to the gas form.
NOTE that in Physical Change there is no change in the chemical structure and the material retains all its chemical properties, and no new compounds are produced.
again, A physical change is any change not involving a change in the substance's chemical identity. Matter undergoes chemical change when the composition of the substances changes: one or more substances combine or break up (as in a relationship) to form new substances.Physical changes occur when objects undergo a change that does not change their chemical nature. A physical change involves a change in physical properties. Physical properties can be observed without changing the type of matter. Examples of physical properties include: texture, shape, size, color, odor, volume, mass, weight, and density.
BUT in Chemical Change ( or Chemical Reaction ) there would be change in the chemical nature of the material undergoing a Chemical Change with the production of new compounds.
During the daytime, I have mostly line symmetry.
During the night, I often have almost spherical symmetry.
When you bring two objects of different temperature together, energy will always be transferred from the hotter to the cooler object. The objects will exchange thermal energy, until thermal equilibrium is reached, i.e. until their temperatures are equal. We say that heat flows from the hotter to the cooler object. Heat is energy on the move.
Units of heat are units of energy. The SI unit of energy is Joule. Other often encountered units of energy are 1 Cal = 1 kcal = 4186 J, 1 cal = 4.186 J, 1 Btu = 1054 J.
Without an external agent doing work, heat will always flow from a hotter to a cooler object. Two objects of different temperature always interact. There are three different ways for heat to flow from one object to another. They are conduction, convection, and radiation.
Answer:
Alpha decay will produce a daughter nucleus with more protons and beta decay will produce a daughter nucleus with fewer protons than the parent nucleus has.
Explanation:
<u>Forces</u><u> </u><u>on</u><u> </u><u>Block</u><u> </u><u>A</u><u>:</u>
Let the x-axis be (+) towards the right and y-axis be (+) in the upward direction. We can write the net forces on mass 
as
Substituting (2) into (1), we get
where 
, the frictional force on 
Set this aside for now and let's look at the forces on 
<u>Forces</u><u> </u><u>on</u><u> </u><u>Block</u><u> </u><u>B</u><u>:</u>
Let the x-axis be (+) up along the inclined plane. We can write the forces on as
From (5), we can solve for <em>N</em> as
Set (6) aside for now. We will use this expression later. From (3), we can see that the tension<em> </em><em>T</em><em> </em> is given by
Substituting (7) into (4) we get
Collecting similar terms together, we get
or
![a = \left[ \dfrac{m_B\sin30 - \mu_km_A}{(m_A + m_B)} \right]g\:\:\:\:\:\:\:\:\:(8)](https://tex.z-dn.net/?f=a%20%3D%20%5Cleft%5B%20%5Cdfrac%7Bm_B%5Csin30%20-%20%5Cmu_km_A%7D%7B%28m_A%20%2B%20m_B%29%7D%20%5Cright%5Dg%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%288%29)
Putting in the numbers, we find that 
. To find the tension <em>T</em>, put the value for the acceleration into (7) and we'll get 
. To find the force exerted by the inclined plane on block B, put the numbers into (6) and you'll get 
