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3 years ago

Can someone explain the law of conservation of energy?

1 answer:

5 0

The law of conservation of energy is:

-- Energy can't be created or destroyed.

-- Energy can't just appear out of nowhere. If you suddenly have
more energy, then the 'extra' energy had to come from somewhere.

-- Energy can't just disappear. If you suddenly have less energy,
then the 'missing' energy had to go somewhere.
________________________________________

There are also conservation laws for mass and electric charge.
They say exactly the same thing. Just write 'mass' or 'charge'
in the sentences up above, in place of the word 'energy'.
________________________________________

And now I can tell you that the conservation laws for energy and mass
are actually one single law ... the conservation of mass/energy. That's
because we discovered about 100 years ago that mass can convert
into energy, and energy can convert into mass, and it's the total of BOTH
of them that gets conserved (can't be created or destroyed).

How much mass makes how much energy ?

The answer is E = m c² .

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True or false gravity is a force

mezya [45]

The answer is true because the invention ofthe beto

4 0

3 years ago

While standing outdoors one evening, you are exposed to the following four types of electromagnetic radiation: yellow light from

WITCHER [35]

Answer:

AM radio, FM radio, microwaves, sodium light.

Explanation:

Electromagnetic radiation are waves from electromagnetic field which spread through the space or any other material medium and carries radiating energy. Examples includes X rays, radio waves, Gamma rays, etc. Exposure to high level of electromagnetic radiation could be harmful to human body, on the other hand, science as not been able to prove that exposing humans to low level electromagnetic radiation is harmful to our health.

3 0

3 years ago

PLEASE HELP!!!! Thank you!

V125BC [204]

it would be a chain reaction and a wave

6 0

3 years ago

A man walks along a straight path at a speed of 4 ft/s. A searchlight is located on the ground 6 ft from the path and is kept fo

BARSIC [14]

We are given that,

$\frac{dx}{dt} = 4ft/s$

We need to find $\frac{d\theta}{dt}$ when $x=8ft$

The equation that relates x and $\theta$ can be written as,

$\frac{x}{6} tan\theta$

$x = 6tan\theta$

Differentiating each side with respect to t, we get,

$\frac{dx}{dt} = \frac{dx}{d\theta} \cdot \frac{d\theta}{dt}$

$\frac{dx}{dt} = (6sec^2\theta)\cdot \frac{d\theta}{dt}$

$\frac{d\theta}{dt} = \frac{1}{6sec^2\theta} \cdot \frac{dx}{dt}$

Replacing the value of the velocity

$\frac{d\theta}{dt} = \frac{1}{6} cos^2\theta (4)^2$

$\frac{d\theta}{dt} = \frac{8}{3} cos^2\theta$

The value of $cos \theta$ could be found if we know the length of the beam. With this value the equation can be approximated to the relationship between the sides of the triangle that is being formed in order to obtain the numerical value. If this relation is known for the value of x = 6ft, the mathematical relation is obtained. I will add a numerical example (although the answer would end in the previous point) If the length of the beam was 10, then we would have to

$cos\theta = \frac{6}{10}$

$\frac{d\theta}{dt} = \frac{8}{3} (\frac{6}{10})^2$

$\frac{d\theta}{dt} = \frac{24}{25}$

Search light is rotating at a rate of 0.96rad/s

4 0

3 years ago

Is there any machine that is 100% efficient? why?why not

denis-greek [22]

Answer:

No, it's not there.

Explanation:

For a machine to be 100% efficient, it has to be with an output which is equal to its input. But machines have an out put less than an input, hence efficiency below 100%.

7 0

3 years ago