Why do i need physics for zoology

Select the sentences about the physical nature of light that are true. Check all that apply. Check all that apply. Blue light ha

Phoenix [80]

Correct options:

- Blue light has a wavelength of 750 nm, the longest wavelength of visible light, and red has a wavelength of 500 nm. --> FALSE. It's actually the opposite: blue light has a wavelength of approx. 500 nm, while red has a wavelength of 750 nm, the longest wavelength of visible light.

- Light is electromagnetic radiation, a type of energy embodied in oscillating electric and magnetic fields. --> TRUE. Electromagntic radiation is a type of transverse waves, consisting of electric and magnetic fields oscillating perpendicularly to each other.

- The units of frequency are distance per second. --> FALSE. Frequency is measured in Hertz (Hz), which corresponds to 1/seconds ( $s^{-1}$ .

- The more closely spaced the waves, that is, the longer the wavelength, the more energy there is. --> FALSE. The energy of an electromagnetic wave is inversely proportional to the wavelength:

$E=\frac{hc}{\lambda}$

that means, the longer the wavelength, the less energy there is.

- Grass appears green because it reflects primarily the wavelength associated with green light and absorbs the others. --> TRUE. The color of the objects as we see them corresponds to the color they reflect, while all the other colors are absorbed by the object.

- Light in a vacuum travels at 3.00×108mph. --> FALSE. The units are wrong: the speed of light in a vacuum is $3.00\cdot 10^8 m/s$ .

- Electromagnetic radiation can be characterized by wavelength, amplitude, and frequency. --> TRUE. Wavelength is the distance between two consecutive crests, amplitude is the maximum displacement of the wave relative to the equilibrium position, frequency is the number of oscillations per second.

- The presence of a variety of wavelengths in white light is responsible for the way we perceive colors in objects. --> TRUE. White light consists of many different colors, and depending on which of them are absorbed/reflected by the objects, we perceive them in different ways.

7 0

4 years ago

How do you calculate the following:<br> Final Velocity?<br> Acceleration?<br> and Force?

kicyunya [14]

Wait like the equations, or is there an actual question?

Equations are

Final velocity (Vf) = Initial velocity (Vi) + Acceleration (a) x Time (t)
Acceleration (a) = (Final velocity [Vf] - initial velocity [Vi]) divided by Time (t)
Force (f) = Mass (m) x Acceleration (a)

(Short version)

Vf = Vi + a(t)
a = (Vf - Vi) divided by t
F = m x a

6 0

4 years ago

Read 2 more answers

Can someone help?

laila [671]

Answer:

i) 21 cm

ii) At infinity behind the lens.

iii) A virtual, upright, enlarged image behind the object

Explanation:

First identify,

object distance (u) = 42 cm (distance between object and lens, 50 cm - 8 cm)

image distance (v) = 42 cm (distance between image and lens, 92 cm - 50 cm)

The lens formula,

$\frac{1}{v} -\frac{1}{u} =\frac{1}{f}$

Then applying the new Cartesian sign convention to it,

$\frac{1}{v} +\frac{1}{u} =\frac{1}{f}$

Where f is (-), u is (+) and v is (-) in all 3 cases. (If not values with signs have to considered, this method that need will not arise)

Substituting values you get,

i) $\frac{1}{42} +\frac{1}{42} =\frac{1}{f}\\\frac{2}{42} =\frac{1}{f}$

f = 21 cm

ii) u =21 cm, f = 21 cm v = ?

Substituting in same equation $\frac{1}{v} =\frac{1}{21} =\frac{1}{21} \\\\\frac{1}{v} = 0\\$

v ⇒ ∞ and image will form behind the lens

iii) Now the object will be within the focal length of the lens. So like in the attachment, a virtual, upright, enlarged image behind the object.

7 0

3 years ago

True or false:<br> All of the rivers in the United States are closely monitored For pollution levels

Nutka1998 [239]

All of the rivers in the United States are not monitored closely for pollution levels.

The statement in the question is False

<h3><u>Explanation:</u></h3>

Not all rivers in the United States are closely monitored for their pollution levels. There are volunteers who take responsibility of checking water bodies such as lakes, rivers, streams etc. They take the next step required after finding a water body contaminated.

But to say that all the rivers receive the same amount of attention and action is incorrect. To ensure that all the rivers are clean and pollution free, it would require a lot of man power in the said department which would collect the water samples from all these rivers and send it to labs for checking the pollution level of the particular river. It can be said that the rivers which are situated beside an industrial site, close to a town, will be the priority for checking pollution levels as it would directly cause harm to a small set of population if the toxicity is at an increased level.

3 0

3 years ago

How are longitudinal and transverse waves alike? How are they different?

larisa86 [58]

Answer:

Longitudinal and transverse waves have many similarities and differences.

Explanation:

Similarities:

Mechanical waves can be transverse and longitudinal waves.

Transverse and longitudinal waves both have wavelengths and frequencies.

They both have amplitudes

Both waves can travel through a medium or not, but it depends on whether is an electromagnetic or a mechanical wave.

Differences:

Electromagnetic waves can only be transverse.

The particles of the medium in a longitudinal wave move parallel to the direction (motion) of a wave. It is in this back and forth motion.

The particles of the medium in a transverse wave move perpendicular to the direction (motion) of a wave. This means that there would be right angles showing that they are perpendicular.

Longitudinal waves have rarefactions and compressions.

These rarefactions and compressions are used to measure the wavelength of a wave. For instance, a wavelength in a longitudinal wave is measured from rarefaction to rarefaction

Transverse waves have troughs and crests.

Amplitude in a transverse wave is measured from the midline to the crest of trough.

Amplitude in a longitudinal wave is measured based on how closely packed the particles of the medium are

I hope this helps

4 0

3 years ago