Jak wpłynie na czas oczekiwania na pierwsze ogrzanie wody (pytanie 1) zwiększenie mocy

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the melting of ice, and expla

BlackZzzverrR [31]

<span>Melting of ice is an endothermic process, meaning that energy is absorbed. When ice spontaneously melts, ΔH (change in enthalpy) is "positive". ΔS (entropy change) is also positive, because, becoming a liquid, water molecules lose their fixed position in the ice crystal, and become more disorganized. ΔG (free energy of reaction) is negative when a reaction proceeds spontaneously, as it happens in this case. Ice spontaneously melts at temperatures higher than 0°C. However, liquid water also spontaneously freezes at temperatures below 0°C. Therefore the temperature is instrumental in determining which "melting" of ice, or "freezing" of water becomes spontaneous. The whole process is summarized in the Gibbs free energy equation:
ΔG = ΔH – TΔS</span>

4 0

2 years ago

Two forces F1 = -7.90i + 5.40j and F2 = 9.00i + 7.60j are acting on an object with a mass of m = 6.30 kg. The forces are measure

IceJOKER [234]

Answer:

Propotionality is important

Explanation:

7 0

2 years ago

The minute hand of a wall clock measures 16 cm from its tip to the axis about which it rotates. The magnitude and angle of the d

olya-2409 [2.1K]

Answer:

Explanation:

Given

Minute hand length =16 cm

Time at a quarter after the hour to half past i.e. 1 hr 45 min

Angle covered by minute hand in 1 hr is 360 and in 45 minutes 270

$|r|=\frac{3\times 2\pi r}{4}=75.408 cm$

$Angle =270^{\circ}$

(c)For the next half hour

Effectively it has covered 2 revolution and a quarter

$|r|=\frac{2\pi r}{4}=25.136 cm$

angle turned $=90^{\circ}$

(f)Hour after that

After an hour it again comes back to its original position thus displacement is same =25.136

Angle turned will also be same i.e. $90 ^{\circ}$

7 0

3 years ago

A quantum well is a region of semiconductor or metal film that confines particles to a small region, resulting in quantized ener

murzikaleks [220]

Answer:

226.2 m/sec

Explanation:

We have given $\Delta x=510nm=510\times 106{-9}m$

The plank's constant $h=6.67\times 10^{-34}$

Mass of electron $m=9.11\times 10^{-31}kg$

Now according to Heisenberg uncertainty principle $\Delta v\geq \frac{h}{2\pi m\Delta x}$

So $\Delta v\geq \frac{6.6\times 10^{-34}}{2\times 3.14\times 9.11\times 10^{-31}\times 510\times 10^{-9}}=226.2m/sec$

5 0

2 years ago

Guys are our body made out of 70 percet water?

babunello [35]

Answer:

I'm pretty Sure. Yea look.

Explanation:

Up to 60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.

6 0

2 years ago

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