Answer:
Work done on an object is equal to
FDcos(angle).
So, naturally, if you lift a book from the floor on top of the table you do work on it since you are applying a force through a distance.
However, I often see the example of carrying a book through a horizontal distance is not work. The reasoning given is this: The force you apply is in the vertical distance, countering gravity and thus not in the direction of motion.
But surely you must be applying a force (and thus work) in the horizontal direction as the book would stop due to air friction if not for your fingers?
Is applying a force through a distance only work if causes an acceleration? That wouldn't make sense in my mind. If you are dragging a sled through snow, you are still doing work on it, since the force is in the direction of motion. This goes even if velocity is constant due to friction.
Explanation:
Answer:
D
Explanation:
Scientists use significant figures to avoid claiming more accuracy in a calculation than they actually know.
The heat is exchanged when two different temperature objects come in contact. The energy gained by an ice block is 2.3 Joules.
<h3>What is temperature?</h3>
Temperature is the degree of hotness and coldness of the object.
A 7g block of ice was added to a coffee cup full of 103.4 grams of water. The water had an initial temperature T₁ = 24.5 C and a final temperature T₂ = 19.2 C after all the ice had melted.
Heat lost by water = Heat gained by ice
Qgain = ms(T₂ -T₁ )
Substituting the value for mass of water m =103.4 g= 0.1034 kg , specific heat of water s = 4.18 kJ/kg and temperature values, we get
Qgain = 0.1034 x 4.18 x (24.5 - 19.2)
Qgain = 2.3 Joules
Thus, the energy gained by an ice block is 2.3 Joules.
Learn more about temperature.
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Answer:
energy I think I'm not sure of the answer.
<span>D. Atoms of all elements contain protons, but the number of protons is different for every element.
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