The answer is D) The boy uses force to move the rock a distance
Answer:
Q = 3937.56 J
Explanation:
Heat transferred due to change in temperature is given by :
c is the specific heat of water, c=4.18 J/g-°C
We have, m = 15 g, 
So,
Hence, 3937.56 J of heat is transferred.
Answer:
describes properties characteristic of no more than two electrons in the vicinity of an atomic nucleus or of a system of nuclei as in a molecule
Answer:
0.825 M
Explanation:
The osmotic pressure is a colligative property, that can be calculated using the following expression.
π = M × R × T
where,
π is the osmotic pressure
M is the molarity
R is the ideal gas constant
T is the absolute temperature (24°C + 273 = 297 K)
M = π / R × T = 20.1 atm / (0.08206 atm.L/mol.K) × 297 K = 0.825 M
The copper wire was sanded before burning in order to make sure that copper metal was exposed on the surface of the wire.
Answer: B
Explanation
The copper wire when placed in atmosphere without coating leads to oxidation of copper metal with respect to the impurities present in the atmosphere.
As copper is electropositive in nature, so electronegative ions present in the universe will try to react with copper and the copper will react easily with other elements.
So generally copper wire is coated with color or polymer coating.
In this case, the copper wire without any coating is sanded, so that the eddy sheets or polishing materials on friction with copper wire will remove the impurities by the electrostatic law of conservation of charges and charge transfer.
As the impurities are removed when copper wire is sanded, the copper atoms will be exposed on the surface of the wire leading to burning of copper in the copper wire.
