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3 years ago

What phytophotodermatitis caused by?

Physics

2 answers:

tatiyna3 years ago

8 0

Answer:

Phytophotodermatitis is induced by the action of long wavelength ultraviolet radiation (UVA) on a plant chemical called furocoumarins (psoralens) on the skin surface. Contact with the plant, fruit or vegetable may have been brief and unnoticed.

Explanation:

Paraphin [41]3 years ago

3 0

Phytophotodermatitis happens when certain plant chemicals cause the skin to become inflamed following exposure to sunlight.

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20. Evaluating Data You are looking at a star through a telescope in January.

REY [17]

It is c I took the test

5 0

3 years ago

An observer on Earth sees rocket 1 leave Earth and travel toward Planet X at 0.3c. The observer on Earth also sees that Planet X

Verizon [17]

Answer:

0.625 c

Explanation:

Relative speed of a body may be defined as the speed of one body with respect to some other or the speed of one body in comparison to the speed of second body.

In the context,

The relative speed of body 2 with respect to body 1 can be expressed as :

$u'=\frac{u-v}{1-\frac{uv}{c^2}}$

Speed of rocket 1 with respect to rocket 2 :

$u' = \frac{0.4 c- (-0.3 c)}{1-\frac{(0.4 c)(-0.3 c)}{c^2}}$

$u' = \frac{0.7 c}{1.12}$

$u'=0.625 c$

Therefore, the speed of rocket 1 according to an observer on rocket 2 is 0.625 c

5 0

3 years ago

A dart is loaded into a spring-loaded toy dart gun by pushing the spring in by a  distance d. For the next loading?the spring is

Mrac [35]

Answer:

$W'=\dfrac{W}{9}$

Explanation:

The potential energy of the spring or the work done by the spring is given by :

$W=\dfrac{1}{2}kd^2$ ............(1)

k is the spring constant

d is the compression

When the spring is compressed a distance d' = d/3, let W' is the work is required to load the second dart. Then the work done is given by :

$W'=\dfrac{1}{2}kd'^2$

$W'=\dfrac{1}{2}k(d/3)^2$ .............(2)

Dividing equation (1) and (2) :

$\dfrac{W}{W'}=\dfrac{1/2kd^2}{1/2k(d/3)^2}$

$\dfrac{W}{W'}=9$

$W'=\dfrac{W}{9}$

So, the work required to load the second dart compared to that required to load the first is one-Ninth as much. Therefore, the correct option is (E).

7 0

3 years ago

When an excited electron in a hydrogen atom falls from the n = 3 to the n = 2 level, a photon of red light is emitted from the a

Kaylis [27]

Answer: 653.33 nm ; 1875, 24 nm

Explanation: For the first case we have to use the Balmer series for the hydrogen when the atom falls from the n = 3 to the n = 2. So for the second transtions for the hydrogen we use the Paschen serie. To do the calculation we need to know the Ryberg constant that is equal to 1.097 * 10^7 m^-1. In the attach is shown the expression for spectral series used for calculation.

3 0

3 years ago

Explain how heat is related to temperature and thermal energy...

daser333 [38]

Answer:

Thermal energy is directly related to heat because thermal energy is how heat is transfered.

5 0

3 years ago