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kumpel [21]
3 years ago
15

LED light bulbs are more energy efficient, last longer, cost more, and have a smaller environmental impact from manufacture to r

ecycling or disposal. The question is which costs less: incandescent, compact fluorescent (CFL), or LED lights?
(a) Ignore the time value of money. What is the average cost per hour for 25,000 hours of light-mg in a community with exist0.15/kWh electricity: for each choice?
(b) If the light is on 5%, 30%, or 60% of the time, how long until does it take for the 25,000 hours?
(c) Which type of light should a homeowner buy?
Physics
1 answer:
Nadusha1986 [10]3 years ago
5 0

Answer:

a) Cost_incandescent  = $ 375 , Cost _CFL = $ 75 , Cost_LED = $ 45

b)  total = 20833 days ,  total_day = 3472 days ,  Total_days = 1736 d

c) LED

Explanation:

This problem is interesting to solve it, we must have a very important factor, such as the equivalence of the light emitted by the three systems, let's perform the calculation for a light intensity of 1000 lumen in the three bulbs.

consumed potence

         incandescent 100W = fluorescent (CFL) 20W = Led 12 W

Now if we can solve your exercise

a) Let's find the power consumed by each type of bulb in the 25000 h

          E = P t

incandescent

             E_incandescent = 100 25000

             E_incandescent = 2.5 105 Wh

             E_incandescent = 2.5 103 kWh

Fluorescent (Low Power) CFL

               E_CFL = 20 25000

               E _DFL = 5 102 kWh

LED

               E_LED = 12 25000

               E_LED = 3 102 kwh

               

Let's use a direct rule of proportions (rule of three) for the cost of energy, if 1 kWh costs $ 0.15, the energy calculates how much it costs

incandescent

                 Cost_Incandescent = 2.5 103 kW / h ($ 0.15 / 1kWh)

                 Cost_incandescent = $ 3.75 102 = $ 375

CFL

                  Cost_CFL = 5 102 0.15

                  Cost _CFL = $ 75

LED

                  Cost_LED = 3 102 0.15

                   Cost_LED = $ 45

Here we do not take into account the possibility of burning incandescent bulbs and there is an extra replacement cost

b) for this part we use direct proportion rules

If the day has 24 hours and the light is on for 5%, how many days are 25000 hours?

     for 5% = 0.05

hours on in a day

         #_hoursdays = 24 hrs 0.05 = 1.2 hrs

total days

          total = 25000 / 1.2

          total = 20833 days

for 30% = 0.30

       # _hoursday = 24 0.30 = 7.2 h

       Total_days = 25000 h (1 day / 7.2 h)

        total_day = 3472 days

for 60% = 0.602

         #_hours = 24 0.60 = 14.4 h

         Total _days = 25000h (1day / 14.4 h)

          Total_days = 1736 d

c) you should decide between the CFL and the Led are much lower.

Between these two should take into account the cost of the bulbs, if we only take into account the cost of the energy consumed, the selection should be LED

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Blababa [14]

Answer:

Explanation:We should know that weight = mass * gravity.

That is weight equals mass times gravity.

Gravity is a force of attraction between any two bodies in the universe. It is directly proportional to product of their masses and inversely proportional to the square of the distance between them.

Gravity is generally measured in terms of acceleration due to gravity, denoted as g. For Earth it is, 9.8 m/s². And for moon, it is about 1.62 m/s².

On Earth, your weight is 70 kg = W

W = mass x 9.8

70 = mass x 9.8

Your mass is 70/ 9.8

i.e approximately 7.14

Weight at the Moon, W' = 7.14 x 1.62

Hence, your weight on the surface of the moon is just 11.56 kg.

Congratulations, you've lost about 58.14 kilograms without any hard exercise. And you're as light as a Sweedish Vallhund! Cheers!

3 0
3 years ago
A 15.0 Ohms resistor is connected in series to a 120V generator and two 10.0 Ohms resistors that are connected in parallel to ea
Nostrana [21]

Hi there! :)

Reference the diagram below for clarification.

1.

We must begin by knowing the following rules for resistors in series and parallel.

In series:
R_T = R_1 + R_2 + ... + R_n

In parallel:
\frac{1}{R_T} = \frac{1}{R_1} + \frac{1}{R_2} + ... + \frac{1}{R_n}

We can begin solving for the equivalent resistance of the two resistors in parallel using the parallel rules.

\frac{1}{R_{T, parallel}} = \frac{1}{10} + \frac{1}{10}\\\\\frac{1}{R_{T, parallel}} = \frac{2}{10} = \frac{1}{5}\\\\R_{T, parallel} = 5\Omega

Now that we have reduced the parallel resistors to a 'single' resistor, we can add their equivalent resistance with the other resistor in parallel (15 Ohm) using series rules:
R_T = 15 + 5\\\\\boxed{R_T = 20 \Omega}

2.

We can use Ohm's law to solve for the current in the circuit.

i = \frac{V}{R_T}\\\\i = \frac{120}{20} = \boxed{6 A}

3.

For resistors in series, both resistors receive the SAME current.

Therefore, the 15Ω resistor receives 6A, and the parallel COMBO (not each individual resistor, but the 5Ω equivalent when combined) receives 6A.

In this instance, since both of the resistors in parallel are equal, the current is SPLIT EQUALLY between the two. (Current in parallel ADDS UP). Therefore, an even split between 2 resistors of 6 A is <u>3A for each 10Ω resistor</u>.

4.

Since the 15.0 Ω resistor receives 6A, we can use Ohm's Law to solve for voltage.

V = iR\\\\V = (6)(15) = \boxed{90 V}

4 0
1 year ago
The 1350-kg car has a velocity of 24 km/h up the 8-percent grade when the driver applies more power for 18 s to bring the car up
Brrunno [24]

Answer:

Explanation:

We shall apply concept of impulse to solve the problem  .

Impulse = force x time

impulse = change in momentum

force x time = change in momentum

initial speed u = 24 km/h = 6.67 m /s

final speed v = 65 km/h = 18.05 m /s

change in momentum = m v - mu

= m ( v-u )

= 1350 ( 18.05 - 6.67 )

= 15363 kg m/s

F x 18 = 15363

F = 853.5 N .

4 0
3 years ago
A train accelerates to a velocity of 500 m/s over time of 2s. The acceleration it experienced was 50m/s2. What was its initial v
ValentinkaMS [17]

Explanation:

We know ,

  • v = u + at
  • u = v - at
  • u = 500 - 2*50
  • u = 400 m/s
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Of gold, oxygen, iron, and sulfur, which is a renewable source?
Ulleksa [173]
Oxygen bc plants go through photosynthesis which keeps producing more oxygen
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