W = Fd = 4(2100) = 8400 J
So the answer is A) 8400 J
I was just rewriting my notes on the work lesson I did in class today, so I saw this question at the perfect time!! :)
Hope it helps!! :)
Answer:
D. infinitely extended in all directions
Explanation:
A semi infinite solid is infinitely extended in every direction. It has a single surface and can extend when heat is applied.
The body of a semi infinite solid is idealised, that is, when there is heat present, it expands in all directions to infinity. It can be used for a thick wall because its shape can be changed when subjected to different levels of heat near its surface.
It is also expands as heat is applied because its thickness is negligible.
This idealized body is used for earth, thick wall, steel piece of any shaped quenched rapidly etc indetermining variation of temperature near its surface & other surface being too far to have any impact on the region in short period of time since heat doesn’t have sufficient time to penetrate deep into body thus thickness can be neglected
The amount of energy needed is 2093 J
Explanation:
The amount of energy needed to increase the temperature of a substance by 
is given by the equation
where
m is the mass of the substance
C is its specific heat capacity
is the increase in temperature
For the water in this problem, we have
m = 50.0 g = 0.050 kg
(specific heat capacity of water)
Therefore, the amount of energy needed is
Learn more about specific heat capacity:
brainly.com/question/3032746
brainly.com/question/4759369
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The force is opposite to the displacement
