Explanation:
Formula to calculate work done by motor is as follows.
Work done by motor = 
where, g = gravitational constant = 10 
Therefore, work done by motor is as follows.
Work done by motor = 
= 100.0 J
Now, heat lost by water will be calculated as follows.
q = 
= 
= 10.0 J
Hence, heat gained by motor = heat lost by water
As, heat gained by motor = 10.0 J
So, change in energy = heat gained - work done
Therefore, change in energy will be calculated as follows.
Change in energy = heat gained - work done
= (10.0 J) - (100.0 J)
= -90.0 J
Thus, we can conclude that change in the energy of the battery contents is -90.0 J.
HF and NaF - If the right concentrations of aqueous solutions are present, they can produce a buffer solution.
<h3>What are buffer solutions and how do they differ?</h3>
- The two main categories of buffers are acidic buffer solutions and alkaline buffer solutions.
- Acidic buffers are solutions that contain a weak acid and one of its salts and have a pH below 7.
- For instance, a buffer solution with a pH of roughly 4.75 is made of acetic acid and sodium acetate.
<h3>Describe buffer solution via an example.</h3>
- When a weak acid or a weak base is applied in modest amounts, buffer solutions withstand the pH shift.
- A buffer made of a weak acid and its salt is an example.
- It is a solution of acetic acid and sodium acetate CH3COOH + CH3COONa.
learn more about buffer solutions here
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Wind becuase you can feel it whhich is physical
The excess reactant is Aluminum.
<u>Explanation:</u>
We have to write the balanced equation as,
4 Al+ 3 O₂ → 2 Al₂O₃
According to the molar ratio 4: 3, from the given balanced equation, we can say that 4 atoms of Al reacted with 3 molecules of oxygen.
Given that 10 atoms of aluminum reacts with 6 molecules of oxygen, as per the ratio only 8 atoms of Aluminum is required to react with 6 molecules of oxygen, so excess reactant is Aluminum.
Answer:
- <u>1. Since the temperature of your body is higher than the temperature of the air and of the water, heat will flow from your body to the air and pool.</u>
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- <u>2. The pool feels cooler than air because the water can absorb heat energy faster than the air, due to liquids are better conductors than gases.</u>
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Explanation:
Heat always flows from warmer substances to colder ones.
The normal body temperature is 98ºF. Therefore, the heat will flow from your body to the air and pool, which are at a lower temperature of 80ºF. In both cases, you will lose thermal energy and the external parts of your body will cool down.
The difference between both cases is in the heat conduction capacity of both air and water.
Liquids (and solids) are better <em>thermal conductors </em>than gases because the conduction of heat occurs as result of the direct contact between the particles of matter: the atoms or molecules in hot matter vibrate faster than their neighbors and transmit them kinetic energy by direct contact.
Therefore, the liquid water in the swimming pool, at the same temperature than the air, will be able to absorb more heat in the same time from the body.
In conclusion, the body will cool down faster in water than in air which is why the pool feels cooler than air.
