Heat lost or gained, H = mc(θ₂ - θ₁)
Where m = mass, c = Specific heat capacity, θ₂= final temperature, θ₁ = initial temperature
m = 200g, c = 0.444 J/g°C, θ₁ = 22 °C (Since it was cooled).
H = 6.9 kj = 6.9 *1000J = 6900 J
6900 = 200*0.444* (θ₂ - 22)
6900/(200*0.444) = θ₂ - 22
77.70 = θ₂ - 22
θ₂ - 22 = 77.7
θ₂ = 77.7 + 22 = 99.7
So initial temperature before cooling ≈ 100°C . Option C.
Answer: 1,500m/s
Explanation:
Relationship existing between velocity of a wave (v), wavelength(¶) and frequency(f) is
v = f¶... (1)
Since Frequency (f) is the reciprocal of the period (T);
Frequency = 1/Period i.e F = 1/T... (2)
Substituting equation 2 into 1 we have;
v = 1/T × ¶
v = ¶/T
Given wavelength ¶ = 9m
Period T = 0.006s
v = 9/0.006
v = 1,500m/s
The velocity of the wave will be 1,500m/s
The force on charge Y is the same as the force on charge X
Explanation:
We can answer this problem by applying Newton's third law of motion, which states that:
"When an object A exerts a force on object B (action force), then object B exerts an equal and opposite force on object A (reaction force)"
In this problem, we can identify object A as charge X and object B as charge Y. The magnitude of the electrostatic force between them is given by
(1)
where:
is the Coulomb's constant
are the two charges
r is the separation between the two charges
According to Newton's third law, therefore, the magnitude of the force exerted by charge X on charge Y is the same as the force exerted by charge Y on charge X (and it is given by eq.(1)), however their directions are opposite.
Learn more about Newton's third law:
brainly.com/question/11411375
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Answer:

Explanation:
Here at thermal equilibrium we can say that thermal energy given by Hot coffee is equal to the thermal energy absorbed by ice cubes
So here we have

now since ice cubes are added into coffee when it is at melting temperature
So here we can say that final temperature of coffee is T degree C
Now we have

here we have

L = 333 kJ/kg = 333 J/g[/tex]



now we have



