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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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Dolphin echolocation is similar to ultrasound. Reflected sound waves
s344n2d4d5 [400]

Answer:

Waves with high frequencies have shorter wavelengths that work better  than low frequency waves for successful echolocation.

Explanation:

To understand why high-frequency waves work better  than low frequency waves for successful echolocation, first we have to understand the relation between frequency and wavelength.

The relation between frequency and wavelength is given by

λ = c/f

Where λ is wavelength, c is the speed of light and f is the frequency.

Since the speed of light is constant, the wavelength and frequency are inversely related.

So that means high frequency waves have shorter wavelengths, which is the very reason for the successful echolocation because waves having shorter wavelength are more likely to reach and hit the target and then reflect back to the dolphin to form an image of the object.

Thus, waves with high frequencies have shorter wavelengths that work better  than low frequency waves for successful echolocation.

3 0
3 years ago
The blades in a blender rotate at a rate of 7700 rpm. when the motor is turned off during operation, the blades slow to rest in
Tpy6a [65]

Angular acceleration = (change in angular speed) / (time for the change)

Change in angular speed = (speed at the end) - (speed at the beginning)

For this fan, speed at the end = 7700 rpm, speed at the end = 0 .

Change in angular speed = -7700 rpm

Angular acceleration = (-7700 rpm) / (2.5 sec)

<em>Angular acceleration = -3,080 rev per minute / sec</em>

That's a perfectly good and true answer to the question, but the units are ugly.  We really need to fix the units, and convert them into something prettier before we hand in this assignment.

1 rev = 2π radians, and

1 minute = 60 seconds .

So

Angular acceleration =

(-3,080 rev/min-sec) · (2π rad/rev) · (1 min/60 sec)

AngAccel = (-3,080 · 2π · 1 / 60) · (rev·rad·min / min·sec·rev·sec)

AngAccel = ( -102 and 2/3 · π) · (rad/s²)

<em>AngAccel = -322.5 radian/s²</em>

7 0
3 years ago
Resistance of a conductor is directly proportional to length.<br> a. True<br> b. False
PtichkaEL [24]

If everything else is held constant ... the substance from which
the conductor is formed, its cross-sectional area, its temperature
everywhere along its length ... then yes, its resistance will be
directly proportional to its length.

4 0
4 years ago
An object's inertia causes it to come to a rest position.
stellarik [79]

Answer:

no

Explanation:

the inertia of an object does not make it to come to rest, this is normally caused by friction

3 0
2 years ago
Ten different uses for solar energy?
baherus [9]

Answer:

for your computer, refridgerator, stove, car, lights, oven, microwave, electronic chargers, wi-fi router, and fans

Explanation:

also solar energy will save the earth from being inhabitable

hope this helped!!

8 0
3 years ago
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