Experimental prac (1 Viewer)

[peony]

In the dot point: perform an investigation to help distinguish non-inertial and inertial frames of reference

i am wondering what are the experimental errors and how i can improve the experiment or what are the ways to improve the accuracy ? I think my teacher skipped this dot point

thank you

 

[Xayma]

What investigation did you carry out? We need to know how it was done before we can go into experimental errors.

 

[Constip8edSkunk]

well i guess the simplest would b 2 just chuck a ball upward in the air, if inertial, it should fall straight down, if not, it'll fall away from its original position... i guess u can say there are errors when you dont chuck the ball exactly straight( which can only b minimised) and atmospherical disturbances. it can b improved by buiilding some device that does the above? and blocks out wind etc...

 

[peony]

We didn't do one, but what are the experimental errors in your prac ?

 

[Xayma]

Originally posted by peony
We didn't do one, but what are the experimental errors in your prac ?

Ahh ok, well we havent done ours yet (were behind a bit because our school doesnt start the HSC course till like week 4). But you will always have human error, differing conditions (when you repeat the prac), etc. Somebody else should be able to give you more.

 

[CHUDYMASTER]

Well we did the "accelerometer" experiment. You make one simply by dangling a mass (pendulum) from a movable trolley. At the end of the trolley, a string with another mass is attached.

Hold the string over a table and let the mass go, this will cause the trolley to move. Then you observe that as the trolley moves, the pendulum should move from side to side, indicating a non-inertial frame of reference. It is non-inertial because it is accelerating due to gravity.

To demonstrate inertial frames of reference, merely move the trolley along across the table and observe no relative movement between the pendulum and the trolley.

As for experimental error, you could say that wind resistence may cause the pendulum to move. To fix this, I saw an interesting model, where you place the pendulum inside a conical flask, filled with water and a rubber stopper at the end. Place THIS on the trolley and the motion of the pendulum would be easily observable.

Hope that works for you...

 

[mazza_728]

I feel so behind

 

[lil_star]

The expt I had...!

I think my expt is easier to remember:


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o
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(the pendulum must be in centre..i tried but mine wont appear in the centre!)

-A dark room (means a room with no doors/windows or doors/windows closed) , with a pendulum hanging in the middle.

-if its an inertial frame of reference OR the room is stationary the pendulum will not move; since inertial --> a = 0
F = ma
F= m *0
F = 0 --> thus the pendulum doest move at all!

- if it is a non inertial frame of reference, the pendulum will move (non inertial = accelerating frame)....thus F = ma

F = ma
a (acceleration) has some value when the pendulum is moving (since acceleration comes from the motion of the room)
thus F Newtons is the force experienced by the pendulum; thus the pendulum moves.

Errors....grrr im not sure....

But what i have written above.......u'd be able to get near full marks, esp its good to add equations, in physics, its not necessary that u always write the answer in words, u can manipulate equations to demonstrate your answers!

hey....ur teacher only skipped ''this'' dot point...i think my teacher skipped ALL....i had to do em with my tutor!

 

[CHUDYMASTER]

Essentially our pracs are the same, but I'm kind of going by the book's practical set-out (Jacaranda)

 

[lil_star]

i think jacaranda pracs have whole lot of crap in there! well thats my view.

 

[peony]

Re: The expt I had...!

Originally posted by lil_star

hey....ur teacher only skipped ''this'' dot point...i think my teacher skipped ALL....i had to do em with my tutor! [/B]

i am guessing my teacher will continue to skip dot points on pracs . cos i had the same teacher last year we didn't do any pracs.
I guess i have to post here more often to learn about it.

 

[Dash]

Dunno if someone has said this one before.
But just have a simple mass dangle from the moving/stationary object from a string.
If it does move, then its accelerating if not, then it is stationary or at constant velocity.
I guess the only error that could occur in this experiment would be if something came into contact with the mass.
Causing it to move, and hence display inaccurate results.
For those who are worried, I don't think that its a prac worth stressing over.
Its pretty simple, since it only requires you to distinguish between an inertial and non-intertial frame of reference.
I doubt any calculations will be required either.

 

[lil_star]

Re: Re: The expt I had...!

Originally posted by peony
i am guessing my teacher will continue to skip dot points on pracs . cos i had the same teacher last year we didn't do any pracs.
I guess i have to post here more often to learn about it.

lolz dont worry ur teacher will only miss pracs....mine missed ALL dot points,,...but nice of him he gave us this disc with all pracs...