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2 years ago

Why might exposing astronauts to weightlessness be harmful?

1 answer:

5 0

The body doesn't have to work as hard when there's no gravity for it to work against, so it becomes accustomed to a much lower work load on every level. It leads to lower bone mass and weaker muscles, including the heart, leading to a drop in blood pressure that can eventually build up to create problems with cognitive function. After so long, minor accidents can lead to major, even life threatening problems. A simple bump that would do little more than leave a bruise on you and I can result in a broken femur bone or broken neck on an astronaut who has been exposed to a weightless environment for too long.

This is one of the several hurdles that must be overcome in order for a manned mission to Mars to succeed. Exposure to a weightless environment on the order of roughly two years for a manned Mars mission would be so degrading to the body that the rough, turbulent re-entry into Earth's atmosphere might prove to be too violent for an astronaut to survive.

The problem is bones.

On Earth, every time you do something with "impact" (like walking), there are microcracks in your bones. Calcium is used by the body to fix these cracks... and that is how the bones grow and become strong.

No weight = no impact = no cracks = no "repairs" being done by the body = the body gets rid of un-neede calcium and bones become brittle and weak.

There are some other operations in the body that require gravity as a "director", or resistance to movement as a driver of change (think of muscles in the legs, when there is no need to walk).

The organ themelves are (generally) OK since many things can work in any orientation.

Read more about the radioactive :

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5 0

1 year ago

food product with 10 kg mass is being transported to thesurface of the moon,where the acceleration due to gravity is1.624 m/s2;

larisa [96]

Answer:

In SI units 98.1 N, 16.24 N

English units 22.053861 lbf, 3.6509144 lbf

Explanation:

g = Acceleration due to gravity

m = Mass = 10 kg

Weight on Earth

$W=mg\\\Rightarrow W=10\times 9.81\\\Rightarrow W=98.1\ N$

Converting to lbf

$98.1\times 0.22481=22.053861\ lbf$

On Moon

$W=10\times 1.624\\\Rightarrow W=16.24\ N$

Converting to lbf

$16.24\times 0.22481=3.6509144\ lbf$

In SI units 98.1 N, 16.24 N

English units 22.053861 lbf, 3.6509144 lbf

5 0

2 years ago

Volcanologists and seismologist are specialzed in what

antiseptic1488 [7]

The answer is:

They are specialized in geology and geophysics

1) Volcanologists are scientific researchers who study the properties of volcanoes and develop the science of predicting volcanic eruptions accurately.

- Volcanoes are the results of fissures in the earth's crust, from which magma, gases, rocks, and ashes can erupt.

-Volcanic eruptions and their impact on the atmosphere are investigated by specialist geologists known as volcanologists.

A) Volcanologists are scientists who use a variety of sophisticated equipment to measure and analyze volcanic activity, lava, rock, ashes and gases as well as earthquakes caused by eruptions.

B) Also, they measure the magnitude and intensity of explosions, placing them on a scale from 1 to 8 [volcanic explosivity index].

C)Volcanologists monitor both active and dormant volcanoes to try to predict eruptions and minimize adverse effects on people and their environment.

D)Also, they spend a lot of time collecting and analyzing samples of debris, rocks and other products from extinct volcanoes to gain a better understanding of the processes behind the volcanic activity and the impact former eruptions had in shaping the climate.

2) Seismologists are Earth scientists, specialized in geophysics, who study the genesis and the propagation of seismic waves in geological materials.

-Their research aims at interpreting the geological composition and structures of the Earth. In the case of earthquakes, seismologists evaluate the potential dangers and seek to minimize their impact through the improvement of construction standards.

5 0

2 years ago

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In which medium does light travel faster: one with a critical angle of 27.0° or one with a critical angle of 32.0°? Explain. (Fo

Eddi Din [679]

Answer:

Among those two medium, light would travel faster in the one with a reflection angle of $32^{\circ}$ (when light enters from the air.)

Explanation:

Let $v_{1}$ denote the speed of light in the first medium. Let $v_{\text{air}}$ denote the speed of light in the air. Assume that the light entered the boundary at an angle of $\theta_{1}$ to the normal and exited with an angle of $\theta_{\text{air}}$ . By Snell's Law, the sine of $\theta_{1}\!$ and $\theta_{\text{air}}\!$ would be proportional to the speed of light in the corresponding medium. In other words:

$\displaystyle \frac{v_{1}}{v_{\text{air}}} = \frac{\sin(\theta_{1})}{\sin(\theta_{\text{air}})}$ .

When light enters a boundary at the critical angle $\theta_{c}$ , total internal reflection would happen. It would appear as if the angle of refraction is now $90^{\circ}$ . (in this case, $\theta_{\text{air}} = 90^{\circ}$ .)

Substitute this value into the Snell's Law equation:

$\begin{aligned}\frac{v_{1}}{v_{\text{air}}} &= \frac{\sin(\theta_{1})}{\sin(\theta_{\text{air}})} \\ &= \frac{\sin(\theta_{c})}{\sin(90^{\circ})} \\ &= \sin(\theta_{c})\end{aligned}$ .

Rearrange to obtain an expression for the speed of light in the first medium:

$v_{1} = v_{\text{air}} \cdot \sin(\theta_{1})$ .

The speed of light in a medium (with the speed of light slower than that in the air) would be proportional to the critical angle at the boundary between this medium and the air.

For $0 < \theta < 90^{\circ}$ , $\sin(\theta)$ is monotonically increasing with respect to $\theta$ . In other words, for $\!\theta$ in that range, the value of $\sin(\theta)\!$ increases as the value of $\theta\!$ increases.

Therefore, compared to the medium in this question with $\theta_{c} = 27^{\circ}$ , the medium with the larger critical angle $\theta_{c} = 32^{\circ}$ would have a larger $\sin(\theta_{c})$ . such that light would travel faster in that medium.

4 0

2 years ago

You can see yourself in the mirror because?

jok3333 [9.3K]

Mirrors reflect light waves.

3 0

2 years ago

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