3 years ago

The Sankey diagram shows the energy transfers in an LED light bulb.

Physics

1 answer:

vredina [299]3 years ago

7 0

Answer:

B)20%

Explanation:

only the 2j of energy is getting used out of 10j.all other 8j are wasted as heat.

therefore the efficiency=2/10*100=20

You might be interested in

What type of heat do we get from sun

seraphim [82]

The type of heat that the Sun emits is called UV (Ultra Violet) rays. This is a natural type of heat, but it can also be dangerous if you expose yourself to too much UV heat, causing "sunburns", or even skin cancer.

5 0

3 years ago

Read 2 more answers

The initial volume reading in a graduated cylinder is 30 mL. The mass of an irregular shape of an unknown metal piece is 55.3 g.

Vadim26 [7]

Answer:

7.9 $\frac{gr}{cm^3}$

Explanation:

When we put the metal piece in the liquid (which is in the graduated cylinder), how much it goes up is equal to the volume of the piece we inserted.

So now we know that the volume of that piece of unknown metal is 7mL (which is the same as 7 $cm^3$ ).

Density is $\frac{mass}{volume}$ .

So the density of that piece of metal is $\frac{55.3g}{7cm^3}$

Which leaves us with a final density of 7.9 $\frac{gr}{cm^3}$

6 0

3 years ago

Frank has a sample of steel that has a mass of 80 grams if the density is 8g/cm3 what is the volume

nikklg [1K]

Density is mass divided by volume. rho=m/v. So, v=m/rho. In frank's case this is 80/8 = 10 cm^3.

7 0

3 years ago

In a cold winters day, if you left a cup of water sitting outside, it could freeze. Heat is transferred out of the water. Descri

Agata [3.3K]

If you were to sit a hot cup of water out side it would frezze faster

4 0

3 years ago

3. You are flying 2586 miles from San Francisco to New York. An hour into the flight, you are 600

Citrus2011 [14]

Answer:

268.2 m/s (1dp)

Explanation:

600 miles = 965,606m (1mile = 1609.34m)

965606/60 = 16,0943.43 ..... (metres traveled every minute)

16,0943.43/60 = 268.2238 .....

3 0

3 years ago

Read 2 more answers