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tresset_1 [31]
3 years ago
7

The 2 question are on the photo above.

Physics
1 answer:
AlekseyPX3 years ago
3 0
A. power plants burn coal. A fossil-fuel power plant is one that burns fossil fuels such as coal, natural gas or petroleum (oil) to produce electricity.

b. Fossil fuels are called so because they have been derived from fossils, which were formed millions of years ago during the time of the dinosaurs. They are fossilized organic remains that over millions of years have been converted to oil, gas, and coal.

C. they are generally classified as non-renewable resources because they take millions of years to form and known viable reserves are being depleted much faster than new ones are generated.

5.
a. Gravitational potential energy and work done
If an object is lifted, work is done against the force of gravity.
When work is done energy is transferred to the object and it gains gravitational potential energy.
If the object falls from that height, the same amount of work would have to be done by the force of gravity to bring it back to the Earth’s surface.
If an object at a certain height has 2000 J of gravitational potential energy, we can say that:
2000 J of work has been done in getting the object to that height from the ground
and
2000 J of work would have to be done to bring it back to the ground.
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A 5.0 kg bucket of water is raised from a well by a rope. If the upward acceleration of the bucket is 3.0 m/s^2, find the force
Harman [31]
We know that m = 5 kg 
                      a  =  3.0 m/s^2
                      g = 9.8 (since not written, lets assume it's an international standard) 

T - mg =  ma

T = mg + ma

T = (5 . 9.8)  +  (5 . 3 )   

T = 49 + 15
  
T  = 64 N

Hope this helps

3 0
3 years ago
Read 2 more answers
Normal conversation has a sound level of about 60 db. How many times more intense must a 100-hz sound be compared to a 1000-hz s
vampirchik [111]

Answer:

5.65 times

Explanation:

60 db sound is equal to 60 phons sound when frequency is kept at 1000Hz.

But when the frequency of sound  is changed to 100 Hz , according to equal loudness curves , the loudness level on phon scale will be 35 phons.

A decrease of 10 phon on phon- scale makes sound 2 times less loud

Therefore a decrease of 25 phons will make loudness less intense by a factor equal to 2²°⁵ or 5.65 less intense . Therefore intensity at 100 Hz

must be increased 5.65 times so that its intensity matches intensity of 60 dB sound at  1000 Hz  frequency.

6 0
4 years ago
Carbon-14 is the typical radioisotope used to date materials; however, it has a limitation to 40,000 years. A scientist who want
PolarNik [594]

Answer:

the only one of these materials that allows studying processes of a very long period of time is Uranium 238

Explanation:

In a radioactive material, half of the atoms decay each life period, in carbon 14 this period T = 5730 years, so for a time of 40,000 years there are 7 life periods, so there are very few atoms left without decomposing .

To study older samples, materials with a longer life period are needed, let's show the visa time

²³⁸U     T=  4.5 10¹⁰ years

⁹¹Rb     T =  58 s

¹³¹I        T= 8.04 days

⁶⁰Co     T= 5.27 years

Therefore, the only one of these materials that allows studying processes of a very long period of time is Uranium 238

7 0
3 years ago
Read 2 more answers
How long will it take for a car to travel 200 km if it has an average speed of 55 km/hr? ​
andreyandreev [35.5K]

Answer: Approximately 3.65 hours

Explanation:

55 km/h x 3.65 hrs = 200.75 Km/h

4 0
3 years ago
A car sitting at rest begins
tamaranim1 [39]

Answer:

It's 2km

Explanation:

a=2.40

T=15s

Speed=2.40*15

//. =36km/h

Distance=S*T

//. =36*15

//. =540m

5 0
3 years ago
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