Planning an investigation

wishboy SG

'O' lvl standard
I need help with planning an experiment to investigate how the stability of objects is affected by their base area.

Common apparatus:

Other apparatus can be requested, subject to availability.
I'm not sure how to investigate. Pls help if can, thanks.

SBS n SMRT SG

simple lah

Place the wodden board flat, standing on the narrow side and wide side, had to push the wooden blocks at the board at the similar forces at the various lengths, the one which the woden block hit and fell at the furthest length is the most stable one.

Is it SPA3??? Plot a graph if it is so and state experimental errors and precautions.

wishboy SG

yup this is SPA skill 3

i dun quite understand the bolded part

"Place the wodden board flat, standing on the narrow side and wide side, had to push the wooden blocks at the board at the similar forces at the various lengths"

and where do i place the wooden blocks?

other stuff such as plotting graph, source of error, conclusions those i noe how to do
jus dun have any idea on how to go abt conducting the experiment

zhenhong SG

Secondly, as to add to wishboy, How do you push the wooden blocks at similar forces?

zhenhong SG

Lastly, as to the plotting graph part, which is the independent and dependent variables? Is your graph plotted with volume of the blocks against the distance travelled? If so, what does the gradient, Vol/dist, means?

But somehow I got the idea behind it, thanks SBS and SMRT.. maybe u can explain why the furthest length is the most stable one? if something is stable, as it falls, shouldn't it be nearer to the table? Because the trajectory path of the wooden blocks can easily reach to a straight line, due to the lower centre of gravity.. this is what i think, which may not be correct.. mind explaining plz?

Thanks though

SBS n SMRT SG

That was just a line of thoughts for you all to develope on, not a percise proceedure, only thinked so far...sorry for not much a help...

dibilo SG

Easy. Stability right?

place a wooden block under the ruler so that the ruler is slanted

start piling blocks of large surface area one on top of the other until the structure crumbles

repeat the experiment and pile smaller blocks till structure falls

u will notice the smaller the blocks (smaller surface) will fall easier

u can further repeat the experiment at different angles to verify findings

Alternatively, since u are given masking tape, then dun waste. build structures of smiliar height but different base area, tape them up, place on the slanted ruler and show that at the same angle, 1 falls and 1 dun

Theory behind is centre of gravity of the 2 different structures. read them up when u do report.

wishboy SG

thanks for the ideas

i was wondering if i could place the blocks on the ruler, one at a time, and stick them on one side to the ruler with masking tape (it is to ensure tat the block doesn't slide down)
den lift the ruler up until the block topples and measure the angle between the ruler and table

dibilo SG

thanks for the ideas

Then ur experiment will lack accuracy. nothing in ur experiment must be done by hand.. as in how do u ensure that when u lift the ruler ur hand can remain still all the time for the measurement?

yes u can stick the blocks like u mentioned (masking tape to be used as double sided tape).

u can still manipulate the slant angle by setting the wooden block under the ruler further or away from the centre of the ruler.
if you do that, measure the angle, record down, secure ur set up and start placing wooden blocks on it. using the same condition, use smaller blocks.

another way to do it is to have 2 blocks of same height but different base and then vary the slant angle in STEP (eg: 5deg/10deg/15deg/20deg). see how far can the one with larger base and smaller base can go before it topples.

one thing u must think of is how to let the blocks topple instead of it sliding off the ruler as the angle increases.

I can draw u the full set up but since this is ur project u gotta think abit.