The power used by Alex to drag the log across the yard is determined as 2,656 W.
<h3>Mass of the log</h3>
The mass of the log is calculated as follows;
W = mg
m = W/g
m = (400)/9.8
m = 40.82 kg
<h3>Velocity of the log</h3>
K.E = ¹/₂mv²
v² = 2K.E/m
v² = (2 x 900)/(40.82)
v² = 44.096
v = 6.64 m/s
<h3>Power used by Alex</h3>
P = Fv
P = 400 x 6.64
P = 2,656 W
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Answer: Option (A) is the correct answer.
Explanation:
When energy is transferred from the air to the water then energy is absorbed by the water molecules.
This energy travels through one molecule of water to another molecule of water by the process of convection.
Thus, we can conclude that when energy is transferred from the air to the water, then it travels through the water.
One: looks to be correct for both answers. Certainly the first one is. The second depends on your other choices. But military use is one.
Two: is correct. Pd has (in this case) an atomic mass of 114 and its number is 46
Three: Even with my slop numbers, 4.98 is the answer (although I get 4.99 but again, my numbers are pretty sloppy).
Four: Slop numbers say 78.3, but 78 is the right answer.
Five: Slop numbers agree with Al2S3. I think that's D
They are all correct. Very Fine Work.
<u>Answer:</u> The 
for the reaction is -1835 kJ.
<u>Explanation:</u>
Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.
According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.
The given chemical reaction follows:
The intermediate balanced chemical reaction are:
(1) 
( × 4)
(2) 
The expression for enthalpy of the reaction follows:
![\Delta H^o_{rxn}=[4\times (-\Delta H_1)]+[1\times \Delta H_2]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B4%5Ctimes%20%28-%5CDelta%20H_1%29%5D%2B%5B1%5Ctimes%20%5CDelta%20H_2%5D)
Putting values in above equation, we get:
Hence, the for the reaction is -1835 kJ.
Answer:
272 m/s
Explanation:
The boy jogs= 250 m
time he takes 110 seconds
average speed = 250/110
272 m/s
