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I need to find information on the possible methods available to measure acceleration due to gravity (symbol g). Some ways are: strobe flash photography, a ticker timer, and a data logger. However, i cannot find any sites with much information on these.

Does anyone know any sites, or has some information?

Many Thanks

Does anyone know any sites, or has some information?

Many Thanks

Most accurate method in a school lab uses the period of a simple pendulum

^^ yeap pendulum is best way

Pendulum Method

T = 2 pi sqrt(L/g), where T = period, L = length of pendulum

So, squaring both sides gives

T^2 = (4 pi^2)/g * L

Measure the period for different lengths of pendulums. Then plot T^2 against L.

Find the gradient, and then you can use this gradient to work out g.

Feel free to ask if you need more help.

T = 2 pi sqrt(L/g), where T = period, L = length of pendulum

So, squaring both sides gives

T^2 = (4 pi^2)/g * L

Measure the period for different lengths of pendulums. Then plot T^2 against L.

Find the gradient, and then you can use this gradient to work out g.

Feel free to ask if you need more help.

Yeah - but you can get 9.81 to 3sf accurcacy with a pendulum based experiment.

Since dropping a ball is very quick and short of using light gates hard to decent timing, you could roll a marble down a ramp. Using trig you can work out the value of g because you know the distance a marble rolls, the angle of the ramp and the time it takes.

I think Galileo might have done somethign similar (I'm stealing what I think is his idea )

I think Galileo might have done somethign similar (I'm stealing what I think is his idea )

The light gates are a nightmare with the the freefall method. You do it instead with a digi timer that starts when the ball is released and stops when it hits a landing plate.

if you want to use light gates you can measure the acceeration of a trolley down a ramp and then assume that this is the along-ramp component of g (ignoring friction, of course).

if you want to use light gates you can measure the acceeration of a trolley down a ramp and then assume that this is the along-ramp component of g (ignoring friction, of course).

sebbie

nice, your experimental technique must be much better than mine!

- The amplitude of the pendulum isn't too large.

- The pendulum travels in a straight line, not an elliptical orbit.

- You measure the length of string from the centre of the bob (i.e. the centre of mass of the pendulum, as you assume the string has no mass)

- You use your stopwatch correctly

That's it. And you get good results. I remember a boy in my GCSE set who got a perfect correlation for his coursework and he didn't cheat. We even tested his results using a Spearman Rank, and he got 1 (which means perfect correlation).

You need to use a LOT of swings. 100 is good. This means that you need a long piece of very thing thread and a heavy bob.

Don't forget the theoritical formula---g=2h/t^2

To derive it, use any of your practical methods that use a ball which is dropped from rest and then use---

s=ut+1/2at^2

a=g

s=h

u is 0 (because dropped from rest) and therefore, this is the forumula

h=(gt^2)/2 (u is 0 so u * t is zero, so no point writing that)

2h=gt^2 (cross multiplied)

2h/t^2=g (cross multiplied)

g=2h/t^2 (reversed, for clearer understanding)

regards,

ultrapower.

To derive it, use any of your practical methods that use a ball which is dropped from rest and then use---

s=ut+1/2at^2

a=g

s=h

u is 0 (because dropped from rest) and therefore, this is the forumula

h=(gt^2)/2 (u is 0 so u * t is zero, so no point writing that)

2h=gt^2 (cross multiplied)

2h/t^2=g (cross multiplied)

g=2h/t^2 (reversed, for clearer understanding)

regards,

ultrapower.

- chemistry
- Chem enthalpy change
- OCR Chemistry PAG 12.1
- Accuracy
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- Biology practical write up?
- Dimensional Analysis
- Physics Assignment
- Why can I never interpret what the a-level biology exam questions are asking me?
- manipulating units help
- chemistry help?
- AS level chemistry- help!!
- A level chemistry uncertainty question
- Understanding Durometers: A Guide to Hardness Measurement
- How would I answer this question?
- chemistry aqa aslevel %uncertainty question
- Help with dimensional analysis....
- chemistry aqa as level bond enthalpy question
- AQA Chemistry exam question from AS paper 2 2021
- Banked Tracks for Turning 17.6

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