Answer:
232 J/K
Explanation:
The amount of heat gained by the air = the amount of heat lost by the tea.
q_air = -q_tea
q = -mCΔT
q = -(0.250 kg) (4184 J/kg/ºC) (20.0ºC − 85.0ºC)
q = 68,000 J
The change in entropy is:
dS = dQ/T
Since the room temperature is constant (isothermal):
ΔS = ΔQ/T
Plug in values (remember to use absolute temperature):
ΔS = (68,000 J) / (293 K)
ΔS = 232 J/K
Answer:
Answer is explained in the explanation section below.
Explanation:
Solution:
We know from the Coulomb's Law that, Coulomb's force is directly proportional to the product of two charges q1 and q2 and inversely proportional to the square of the radius between them.
So,
F = 
Now, we are asked to get the greatest force. So, in order to do that, product of the charges must be greatest because the force and product of charges are directly proportional.
Let's suppose, q1 = q
So,
if q1 = q
then
q2 = Q-q
Product of Charges = q1 x q2
Now, it is:
Product of Charges = q x (Q-q)
So,
Product of Charges = qQ - 
And the expression qQ -
is clearly a quadratic expression. And clearly its roots are 0 and Q.
So, the highest value of the quadratic equation will be surely at mid-point between the two roots 0 and Q.
So, the midpoint is:
q =
q = Q/2 and it is the highest value of each charge in order to get the greatest force.
<span>When an object travels in a curved path, there must be a force acting toward the center of the circular trajectory. This force is called "centripetal force", and it cause an acceleration of the object, called "centripetal acceleration". The effect of this acceleration is that the velocity of the object changes in direction: however if the circular motion is uniform, the speed (=the magnitude of the velocity) does not change. In this case, the magnitude of the centripetal force is given by
</span>

<span>
where m is the mass of the object, v its velocity, and r the radius of the circular path.</span>
Answer: V=IR
Explanation: for a series circuit connected to a battery supply, the total emf across the circuit is given as
E = I(R + r) and by expanding, we have that E =IR + It
Where r is the internal resistance of the battery
I is the total current flowing in the circuit
R total load resistance in the circuit.
E is the total emf of the circuit.
The total emf is the sum of 2 separate voltages.
"IR" which is the terminal voltage and "Ir" which is the loss voltage.
The teenila voltage is the voltage flowing in the circuit based on the equivalent resistance of the circuit while the loss voltage is the wasted voltage based on the internal resistance of the battery source.
Answer:
Explanation:
All substances have characteristic physical and chemical properties. Physical properties are those that can be observed with the senses without changing the identity of the substance. Chemical properties describe how a substance can be changed into a new substance. Physical and chemical properties, such as color, density, boiling point, solubility, conductivity, and flammability, A. are always different between substances. B. depend on the amount of the substance. C. do not depend on the amount of the substance. D. have the same values for all substances.
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