# Physics

a 75 w compact fluorescent bulb operating at 30% efficiency. Calculate the amount of energy lost to heat and the amount of energy converted into light after the bulb has been on for 2.0h.

1. 👍
2. 👎
3. 👁
1. 2*3600 seconds/h = 7200 seconds

75 * 7200 = 540,000 Joules total electricity use

.7 * 540,000 = heat Joules
.3 * 540,000 = light Joules

1. 👍
2. 👎

## Similar Questions

1. ### science

1.Which car has the greatest efficiency?(1 point) a 900 kg car that travels 15 km per liter of fuel a 900 kg car that travels 20 km per liter of fuel a 1,200 kg car that travels 15 km per liter of fuel a 1,200 kg car that travels

2. ### Physics

1. Light bulbs produce useful energy in the form of light and waste energy in the form of heat. What kind of light bulb would you use to incubate eggs? A) high-efficiency light bulbs because they produce more heat B) High

3. ### physics

An energy-efficient lightbulb, taking in 25.0 W of power, can produce the same level of brightness as a conventional bulb operating at power 100 W. The lifetime of the energy-efficient bulb is 10,000 h and its purchase price is

4. ### Science

1. Light bulbs produce useful energy in the form of light and waste energy in the form of heat. What kind of light bulb would you use to incubate eggs? A) high-efficiency light bulbs because they produce more heat B) High

1. ### Physics

A heat engine operating between 100 degree celcius and 700 degree celcius has an efficiency equal to 40% of the maximum theoretical efficiency. How much energy does this engine extract from the hot reservoir in order to do 5000 J

2. ### Science

We know that the law of conservation of energy states that energy can not be created or destroyed. It only changes form. Consider this energy transformation diagram. Assume that the energy input in this case is chemical potential

3. ### Physics

A heat engine operating b/n 100°c and 700°c has an efficiency equal to 40% of the maximum theoretical efficiency. How much energy does this extract from the hot reservoir in order to do 5000J of machanical work?

4. ### physics

A)When the energy input to gas fired power station is 1000MJ,the electrical energy output is 300MJ.What is the efficiency of the power station in changing the energy in gas into electrical energy b)what form does the 700MJ of lost

1. ### Physics

Which of the following statements is true for an elastic collision? A. Both momentum and kinetic energy are conserved. B. Momentum is conserved, but kinetic energy is not conserved. C. Kinetic energy is conserved, but momentum is

2. ### English

Which of the following statements in a research paper would need citation? A. Washington, D.C. is the capital of the United States. B. The landing on the moon is one of the most exciting events in recent history.*** C.

3. ### PHYSICS

Given: The energy equivalent of one gallon of gasoline is 1.3 × 108 J. A compact car has a mass of 847 kg, and its efficiency is rated at 18.1%. (That is, 18.1% of the input power available is delivered to the wheels.) Find the

4. ### Science

An electric light is plugged into a 120-V outlet. If the current in the bulb is 0.5 A, how much electrical energy is used by the bulb in 15 minutes?