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3 years ago

Which statement describes a controlled experiment?

Physics

1 answer:

olga_2 [115]3 years ago

7 0

Answer:

In a controlled experiment, an independent variable (the cause) is systematically manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled. The researcher can operationalize (i.e. define) the variables being studied so they can be objectivity measured.

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A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions. What is the amplitude of the m

Anna35 [415]

To solve this problem it is necessary to take into account the concepts of Intensity as a function of Power and the definition of magnetic field.

The intensity depending on the power is defined as

$I = \frac{P}{4\pi r^2},$

Where

P = Power

r = Radius

Replacing the values that we have,

$I = \frac{60}{(4*\pi (0.7)^2)}$

$I = 9.75 Watt/m^2$

The definition of intensity tells us that,

$I = \frac{1}{2}\frac{B_o^2 c}{\mu}$

Where,

$B_0 =$ Magnetic field

$\mu =$ Permeability constant

c = Speed velocity

Then replacing with our values we have,

$9.75 = \frac{Bo^2 (3*10^8)}{(4\pi*10^{-7})}$

Re-arrange to find the magnetic Field B_0

$B_o = 2.86*10^{-7} T$

Therefore the amplitude of the magnetic field of this light is $B_o = 2.86*10^{-7} T$

6 0

3 years ago

A galaxy that is a featureless spherical ball of stars would be called a type

satela [25.4K]

Answer:

Explanation:

Yes. The "0" indicates that it is spherical

7 0

3 years ago

Venus is the only inner planet that has been explored by rovers

Vesnalui [34]

I don't know what this question is asking but this statement is false because venus is a planet made of hot gas that cannot be landed on. So venus has not been explored by rovers. (However Mars has been explored by rovers)

8 0

3 years ago

What is the frequency of a photon that has the same momentum as a neutron moving with a speed of 1.90 × 103 m/s?

Minchanka [31]

The mass of a neutron is:
$m=1.67 \cdot 10^{-27}kg$
Since we know its speed, we can calculate the neutron's momentum:
$p=mv=(1.67 \cdot 10^{-27}kg)(1.90 \cdot 10^3 m/s)=3.17 \cdot 10^{-24} kg m/s$

The problem says the photon has the same momentum of the neutron, p. The photon momentum is given by
$p= \frac{h}{\lambda}$
where h is the Planck constant, and $\lambda$ is the photon wavelength. If we re-arrange the equation and we use the momentum we found before, we can calculate the photon's wavelength:
$\lambda= \frac{h}{p}= \frac{6.6 \cdot 10^{-34}Js}{3.17 \cdot 10^{-24} kg m/s}=2.08 \cdot 10^{-10} m$

And since we know the photon travels at speed of light c, we can now calculate the photon frequency:
$f= \frac{c}{\lambda}= \frac{3 \cdot 10^8 m/s}{2.08 \cdot 10^{-10} m}= 1.44 \cdot 10^{18} Hz$

4 0

3 years ago

Please help with this! The selected answer is the incorrect one, I'm making corrections.

elixir [45]

Answer:

The answer is C-Spin a magnet around the wire on the piece of iron. Hope that helps :)

6 0

3 years ago