Q = m.s.Δt
Δt = Q /m.s
Here, Q = 30,000 J
m = 390 g
s = 3.9 J/g C
Substitute their values,
= 30,000 / 390 *3.9
= 30,000 / 1521
= -20 C (approx.) [-ve sign 'cause temperature is decreasing ]
In short, Your Answer would be Option D
Hope this helps!
Answer:
a) the magnitude of the force is
F= Q(
) and where k = 1/4πε₀
F = Qqs/4πε₀r³
b) the magnitude of the torque on the dipole
τ = Qqs/4πε₀r²
Explanation:
from coulomb's law
E = 
where k = 1/4πε₀
the expression of the electric field due to dipole at a distance r is
E(r) = 
, where p = q × s
E(r) = 
where r>>s
a) find the magnitude of force due to the dipole
F=QE
F= Q()
where k = 1/4πε₀
F = Qqs/4πε₀r³
b) b) magnitude of the torque(τ) on the dipole is dependent on the perpendicular forces
τ = F sinθ × s
θ = 90°
note: sin90° = 1
τ = F × r
recall F = Qqs/4πε₀r³
∴ τ = (Qqs/4πε₀r³) × r
τ = Qqs/4πε₀r²
Answer:
Melting tin and then cooling it into a mold
Explanation:
When you melt something, and when it cools it returns to its physical state, therefore the physical changes are reversible. For example, take chocolate. When chocolate melts its liquid, then when it's in a colder situation it becomes solid again and so on, the changes are reversible.
Explanation:
An acid is a substance that interacts with water to produce excess hydroxonium ions, H₃O⁺ in an aqueous solution.
The hydroxonium ions formed by the chemical bonding between the oxygen of water molecules and the protons released by the acid due to its excess ionization.
For example:
HCl + H₂O ⇄ H₃O⁺ + Cl⁻
acid water hydroxonium chloride
A base is a substance that interacts with water to yield excess hydroxide ions, OH⁻ in an aqueous solutions:
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻
Ammonia water ammonium hydroxide
These explanations are based on the arrhenius theory.
learn more:
Bronsted-lowry theory brainly.com/question/4083753
Acid reaction brainly.com/question/5273689
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