All categories

3 years ago

A bulb converts 9J of energy in each second from an input of 100J of energy. Calculate efficiency of this light bulb

1 answer:

8 0

Efficiency is calculated through dividing the actual mechanical advantage by the hypothetical mechanical advantage:

- the actual mechanical advantage is 9J because that's how much work the light bulb doing

- the hypo. mechanical advantage is 100J. Ideally, in a perfect world, the light bulb can convert 100J input into 100J output, but do to resistance and other factors it is not possible.

$\frac{9}{100} = .09$
change the decimal to a percentage:

$.09 = 9\%$
the light bulb had 9% efficiency

You might be interested in

An automobile tire is inflated with air originally at 10.0°C and normal atmospheric pressure. During the process, the air is com

solong [7]

Answer:

(a) $3.81\times 10^5\ Pa$

(b) $4.19\times 1065\ Pa$

Explanation:

<u>Given:</u>

$T_1$ = The first temperature of air inside the tire = $10^\circ C =(273+10)\ K =283\ K$

$T_2$ = The second temperature of air inside the tire = $46^\circ C =(273+46)\ K= 319\ K$

$T_3$ = The third temperature of air inside the tire = $85^\circ C =(273+85)\ K=358 \ K$

$V_1$ = The first volume of air inside the tire

$V_2$ = The second volume of air inside the tire = $30\% V_1 = 0.3V_1$

$V_3$ = The third volume of air inside the tire = $2\%V_2+V_2= 102\%V_2=1.02V_2$

$P_1$ = The first pressure of air inside the tire = $1.01325\times 10^5\ Pa$

<u>Assume:</u>

$P_2$ = The second pressure of air inside the tire

$P_3$ = The third pressure of air inside the tire
n = number of moles of air

Since the amount pof air inside the tire remains the same, this means the number of moles of air in the tire will remain constant.

Using ideal gas equation, we have

$PV = nRT\\\Rightarrow \dfrac{PV}{T}=nR = constant\,\,\,(\because n,\ R\ are\ constants)$

Part (a):

Using the above equation for this part of compression in the air, we have

$\therefore \dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\Rightarrow P_2 = \dfrac{V_1}{V_2}\times \dfrac{T_2}{T_1}\times P_1\\\Rightarrow P_2 = \dfrac{V_1}{0.3V_1}\times \dfrac{319}{283}\times 1.01325\times 10^5\\\Rightarrow P_2 =3.81\times 10^5\ Pa$

Hence, the pressure in the tire after the compression is $3.81\times 10^5\ Pa$ .

Part (b):

Again using the equation for this part for the air, we have

$\therefore \dfrac{P_2V_2}{T_2}=\dfrac{P_3V_3}{T_3}\\\Rightarrow P_3 = \dfrac{V_2}{V_3}\times \dfrac{T_3}{T_2}\times P_2\\\Rightarrow P_3 = \dfrac{V_2}{1.02V_2}\times \dfrac{358}{319}\times 3.81\times 10^5\\\Rightarrow P_3 =4.19\times 10^5\ Pa$

Hence, the pressure in the tire after the car i driven at high speed is $4.19\times 10^5\ Pa$ .

8 0

2 years ago

Which organic compound forms much of the structure of cells?

o-na [289]

Which organic compound forms much of the structure of cells?

Answer: A Carbohydrates

4 0

2 years ago

Read 2 more answers

HELP ME 20 POINTS!!!Assume that the average volume of an adult human body is one-tenth

Agata [3.3K]

Answer:

,Assume that the average volume of an adult human body is one-tenth

cubic meter (0.10 m) and that there are two billion (2.0 x 109)

adults in the world.

a. What would be the total volume of all the adults in the world?

b. Compute the length of one edge of a cubic container that has a

volume equal to the volume of all the adults in the world.

8 0

3 years ago

Read 2 more answers

In both the camera and the __________, light enters a narrow opening and is projected onto a photosensitive surface. Group of an

Citrus2011 [14]

Answer: The HUMAN EYE

Explanation:

The human eye is made up of different parts which ranges from controlling the amount of light that enters the eye to the focusing of the image that is formed. The camera is a device which is both mechanically and electronically operated which shares a number of similarities with the eye.

In the human eye, the IRIS helps to regulate the amount of rays passing through the pupil to the lens by either contracting or dilating in light or dark environment respectively. While in the camera, the DIAPHRAGM controls the amount of light entering the camera.

The PUPIL serves as the passage for light into the eye while in the camera, the APERTURE does the same.

The photosensitive surface in the eye is the YELLOW SPOT while in the camera, the photosensitive surface is the PHOTOGRAPHIC FILM.

5 0

2 years ago

When a driver hits the brakes, his car decelerates from 50m/s at a uniform rate of 2.0m/s^2. His car stops after covering some d

Assoli18 [71]

Please find attached photograph for your answer. Please do comment whether it is useful or not.

7 0

3 years ago