Answer: The friction force.
Justification:
Since the box is sliding over the table, the normal force equals the weight of the object (and any other vertical force that is applied on the box).
So, the normal force and weight (along with any other vertical component of a force applied on the box) must be 10 N and 10 N.
The other two forces: 14 N and 7 N are the forces in the plane of the table and should be opposite in a same line. The 14 N force is the responsible of the motion and the 7N force is opposing the 14 N force, so the 7N force has to be the friction force. Of course, 14N - 7N > 0 which is why the box is moving.
A. Fossil fuels take a very long time to form so we mine it faster than it can replenish.
Answer:
A) ∆Suniv >0, ∆G<0, T∆Suniv >0.
Explanation:
The connection between entropy and the spontaneity of a reaction is expressed by the <u>second law of thermodynamics</u><u>: The entropy of the universe increases in a spontaneous process and remains unchanged in an equilibrium process</u>.
Mathematically, we can express the second law of thermodynamics as follows:
For a spontaneous process: ΔSuniv = ΔSsys + ΔSsurr > 0
Therefore, the second law of thermodynamics tells us that a spontaneous reaction increases the entropy of the universe; that is, ΔSuniv > 0.
If we want spontaneity expressed only in terms of the properties of the system (ΔHsys and ΔSsys), we use the following equation:
-TΔSuniv = ΔHsys - TΔSsys < 0
That means that T∆Suniv >0.
This equation says that for a process carried out at constant pressure and temperature T, if the changes in enthalpy and entropy of the system are such that <u>ΔHsys - TΔSsys is less than zero, the process must be spontaneous.</u>
Finally, if the change in free energy is less than zero (ΔG<0), the reaction is spontaneous in the forward direction.
Answer:
all these are physical properties except release of heat so it's probably heat energy given off
Answer:
Calcium
Explanation:
Since the element reacts with oxygen to form an oxide with the formula MO, the charge on the element is +2.
Also, since the oxide MO when dissolved in water is basic, the metal is an alkali earth metal.
From the above conditions;
The metal is not arsenic because arsenic is a metalloid has the following oxides As₂O₃ and As₃O₅ and are respectively amphoteric and acidic in nature
The metal is not germanium because is a metalloid and even though germanium oxide has the formula GeO₂, it is amphoteric.
The metal is not chlorine because chlorine is a non-metal
The metal is definitely calcium because calcium oxide has the formula CaO and calcium is an alkaline earth metal.
The metal is not selenium because selenium is anon-meal and its oxide has the formula Se0₂ and is acidic
