Answer:
1. 1800 W
2. $ 17.3
Explanation:
From the question given above, the following data were obtained:
Current (I) = 15 A
Voltage (V) = 120 V
Time (t) = 20 h per day
Duration = 31 days
Cost = 15.5 cents per kWh
1. Determination of the power.
Current (I) = 15 A
Voltage (V) = 120 V
Power (P) =?
P = IV
P = 15 × 120
P = 1800 W
Thus, 1800 W of power is required.
2. Determination of the cost per month (31 days).
We'll begin by converting 1800 W to KW.
1000 W = 1 KW
Therefore,
1800 W = 1800 W × 1 KW / 1000 W
1800 W = 1.8 KW
Next, we shall determine the energy consumption for 31 days. This can be obtained as follow:
Power (P) = 1.8 KW
Time (t) = 2 h per day
Time (t) for 31 days = 2 × 31 = 62 h
Energy (E) =?
E = Pt
E = 1.8 × 62
E = 111.6 KWh
Finally, we shall determine the cost of consumption. This can be obtained as follow:
1 KWh = 15.5 cents
Therefore,
111.6 KWh = 111.6 KWh × 15.5 cents / 1 KWh
111.6 KWh = 1729.8 cents
Converting 1729.8 cents to dollar, we have:
100 cents = $ 1
Therefore,
1729.8 cents = 1729.8 cents × $ 1 / 100 cents
1729.8 cents = $ 17.3
Thus, it will cost $ 17.3 per month to run the electric heater.
Answer:
The generation of <u>heat</u>.
Explanation:
The amount of heat needed to increase the temperature of a solid sphere of diameter 2D of the same metal from 4°C to 7°C is is 8 times the initial amount of heat.
<h3>What is heat?</h3>
The temperature increment will lead to the increase in the internal energy of the object. This internal energy is the heat.
Given is the change in temperature ΔT = 7-4 =3°C., diameter D to 2D,
Q = Cp x ρ(4π/3)D³ x 3..................(1)
and Q' = Cp x ρ(4π/3)(2D)³ x 3
Q' = Cp x ρ(4π/3)8D³x 3..................(2)
Dividing both the equation, we have
Q' / Q =8
Q' = 8Q
Thus, the amount of heat needed to increase the temperature of a solid sphere of diameter 2D of the same metal from 4°C to 7°C is 8 times the initial amount of heat.
Learn more about heat.
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We use only one variable at a time to find the accurate result. We want to see how the result of experiment changes everytime with a single variable.
