Need Help With School Project

[Emporius]

My Physics summative is due monday, and I need some help.

For our summative we need to choose 4 everyday activities to do on Mars.

Two must be different as compared to Earth.

Two must be the same as compared to Earth.

Each activity has to cover a different unit, the Units being:

Forces and Motion, Energy Work and Power, Waves and Sound, Light and Geometric Optics, and *Electricity and Magnetism *(we are in the midst of this unit so pref not)

If you guys could help me think of activities that would be greatly appreciated. :cheers:

PS they don't really need to be everyday activities

 

[Emporius]

Bah you all suck

 

[Rapstah]

Going to the bathroom is all about waves and sound.

 

[AJ Rimmer]

Each activity has to cover a different unit, the Units being:

Forces and Motion, Energy Work and Power, Waves and Sound, Light and Geometric Optics, and *Electricity and Magnetism *(we are in the midst of this unit so pref not)

Habbawabba whatsa?

 

[Saturos]

You could attempt to discover ancient alien ruins and use ancient alien artifacts to awaken to forces of hell. Or you could attempt to study teleportation. If these fail, you could also attempt to start a whole new mining corporation based on Mars and call it "Ultor", while enslaving as many humans as possible through trickery and promise of a better life upon returning to Earth.:|

 

[Emporius]

You could attempt to discover ancient alien ruins and use ancient alien artifacts to awaken to forces of hell. Or you could attempt to study teleportation. If these fail, you could also attempt to start a whole new mining corporation based on Mars and call it "Ultor", while enslaving as many humans as possible through trickery and promise of a better life upon returning to Earth.:|

oooooorrrrr I could talk about badminton or...GASP!

HIGH JUMP

 

[Wanted Bob]

Bahaha, I have to do the same thing right now

My advice is DO NOT do sound, it gets pretty complicated. Stick with Electricity, cause there really arent any veriables atm that can interfere with it.

 

[Emporius]

Bahaha, I have to do the same thing right now

My advice is DO NOT do sound, it gets pretty complicated. Stick with Electricity, cause there really arent any veriables atm that can interfere with it.

What 4 things are you doing?

 

[evil^milk]

Physics, hmm. Do you like music? You could probably do some sort of comparison of how music or sound travels trough a different atmosphere such as Mars' or something.

 

[theotherguy]

Forces and Motion

Downhill ski jumping on Olympus Mons. The force of gravity is only 1/3 that of earth's and there is very little wind. Olympus Mons is very very high, so if you had a very long platform made of dry ice, you could ski down it, come off of a ramp and shoot very high into the air.

Energy Work and Power

Things like rotational kinetic energy will be the same on earth as on mars. So, go on a merry go round, and it will be practically the same as a merry go round on earth.

Waves and Sound

The speed of sound is much slower on mars, because there is very little atmosphere. As for an activity.... a live concert perhaps?

Light and Geometric Optics

Same on Earth as on Mars. Look at stuff with a telescope.

*Electricity and Magnetism *(we are in the midst of this unit so pref not)

Mars lacks a magnetic field, so anything you do with a compass will not work. Interestingly enough, you could use a compass to find even very weak sources of magnetism on mars, so perhaps you could hide various magnetic objects and try to use a compass to find them?


]

 

[dfc05]

Light and Geometric Optics

You could use lenses or mirrors to focus sunlight, as in solar electricity generation, or solar water heating. Boring, but useful.

 

[Emporius]

thanks guys, these are great, but if people have more keep em coming

 

[Angry Lawyer]

Off the top of my head:

SAME:
Playing with a flashlight (same - light isn't really affected much)
Jumping (forces and motion - much reduced gravity)

DIFFERENT:
Singing (sound - thinner air means higher pitched voices)
Using a compass (magnetism - Mars doesn't have a proper magnetic field and compasses will spaz out)
Driving fast (Work - less atmosphere means less air to slow you down)

-Angry Lawyer

 

[Saturos]

SAME:Weight lifting maybe? Unless of course there's someway to generate gravity equivalent to Earth's artificially by then, one would suffer mild atrophy to match that of Mars' gravitational field. Meaning one would have to lift at least a third more than what would give a desirable physique on Earth. Probably a third more of a full workout on Earth though in order to work all muscle groups.

DIFFERENT: Soil samples. The Iron Oxide rich samples of Mars could help in research in finding ways to provide essential resources while on Mars. (Guess where I got this from ) This would probably fall under the Energy Work and Power topic, since one needs essential resources for "Work and Power"

 

[Angry Lawyer]

Weightlifting would be hugely different, considering everything would weight something like a third of what it does on Earth.

-Angry Lawyer

 

[Saturos]

Weightlifting would be hugely different, considering everything would weight something like a third of what it does on Earth.

-Angry Lawyer

I misunderstood then. Does the activity have to work identical to that of Earth? I did say if there were such a thing as an artifical gravity generator. So does he mean:

SAME=works the same on Earth as it does on Mars

DIFFERENT=works differently on Mars than it does on Earth

 

[morgs]

Play golf?

 

[Dan]

My Physics summative is due monday, and I need some help.

For our summative we need to choose 4 everyday activities to do on Mars.

Two must be different as compared to Earth.

Two must be the same as compared to Earth.

Each activity has to cover a different unit, the Units being:

Forces and Motion, Energy Work and Power, Waves and Sound, Light and Geometric Optics, and *Electricity and Magnetism *(we are in the midst of this unit so pref not)

If you guys could help me think of activities that would be greatly appreciated. :cheers:

PS they don't really need to be everyday activities

Well any physical activity (basketball, walking, skipping rope) will be different because of gravity. Mars has something like 0.6 g. That would involve forces and motion.

The Martian atmosphere is also different (I'm not sure if they have any left, but it would be thin if it exists). That means that sounds will transmit at different speeds or not at all. So playing a radio on mars would be different. That's waves and sound.

 

[repiV]

Riding a motorcycle on Mars would be an interesting experience. The acceleration would be much faster because of the low gravity, but you wouldn't be able to make use of even a fraction of it because the low gravity would also ensure there's hardly any grip available and you'd lose control of the machine if you weren't extremely gentle.
I don't know what the effect on the steering would be. It would hurt a lot less if you came off though.

 

[kirovman]

Having a tug.

 

[repiV]

Having a tug.

Messy cleanup.

 

[Angry Lawyer]

Or, if your hydraulics are good enough, it'll end up in orbit D:

-Angry Lawyer

 

[Wanted Bob]

Thing is with these ideas, is they have to be mathematically proven. So although using a sound comparisson would be great, the equations needed to derive the speed of sound and whatnot are much more complicated that what we have learned.

 

[Gormanmod]

1)cook- same as on earth. kinetic energy?

2)pee- not same as on earth, me guess the rate of acceleration of pee due to gravity.

3)sex- not same as on earth, "impulse" equation :naughty: epic lulz

4) can't think of something same on earth

 

[Dan]

Thing is with these ideas, is they have to be mathematically proven. So although using a sound comparisson would be great, the equations needed to derive the speed of sound and whatnot are much more complicated that what we have learned.

No it's not. Look around a bit on wikipedia:
speed of sound = sqrt(gamma*P/density). We can assume that the Martian atmosphere is 100% carbon dioxide for estimation purposes. It's actually something like 95%. The ambient temperature is somewhere around -10 degrees celsius, or 263 Kelvin.

So gamma, the specific heat ratio (Cp/Cv) for carbon dioxide at this temperature is somewhere around 1.3, maybe a bit less. I just looked it up in a table, but you could calculate it with the equation empirical equations for Cp and Cv at varying temperature.

Anyways, the pressure at the surface of Mars is about 7 millibars, or 709 Pa.

The density of carbon dioxide is given by MP/RT (from Boyle's law). M, the molar mass is just 12+16+16= 44 g/mol. P, pressure is 0.709 kPa. R, the universal gas constant is 8.314 kJ/kmol K. And T, temperature is about 263 K. This gives a final density (at the surface) of 0.014 kg/m^3, about 1% compared to Earth.

Add all of those numbers into the original equation and you get the speed of sound on the surface of mars to be 257 m/s give or take a bit of rounding error. This is about 3/4 the speed of sound on Earth. The main reason for the lower speed is the low pressure of the thin Martian atmosphere.

What this means is that the frequency of any sound generation will be less. c = f*lambda. The speed of sound is equal to the frequency, times the wavelength. What this means is that noise generation on Mars would be equivalent to breathing the opposite of helium, everything is Doppler shifted to a lower pitch because of the lower speed of sound.

Acoustic shadowing is also an interesting affect due to the pressure gradient with altitude. On Earth, because pressure decreases with altitude, sound waves tend to refract upwards very gradually. This means that any sound source close to the ground can have an acoustic shadow (an area where that sound source cannot be heard) a certain distance away from it. Of course it also depends on winds and temperature. For example, this is what prevented General Ulysses S Grant from hearing the battle Iuka. I would imagine that because of the high temperature gradient and the low absolute pressure, Mars would have significant atmospheric refraction. All of the sound would bend upwards (although I can't quantify how much without spending a lot of time on it.)

Write all of that up using whatever lame noise generation example and with some citations (not me) and put the calculations into some math editor with proper units and you will get a good mark.

 

[Angry Lawyer]

Wow, I got it the wrong way round then - I assumed it was akin to talking in helium.

-Angry Lawyer

 

[Emporius]

I just wanted to thank everyone for their ideas. I am currently working on the summative and it is going well :thumbs: