Physics resit soon help a VERY simple graph problem

  • Thread starter Thread starter tommyleehutch
  • Start date Start date
  • Tags Tags
    Graph Physics
AI Thread Summary
The discussion revolves around a high school physics resit focusing on graphing relationships between frequency and time period. The user is uncertain about how to properly express these relationships, particularly whether to graph frequency squared against time or frequency against the square root of time. There are also questions about rounding uncertainties in measurements and the conventional placement of time on graph axes. It is emphasized that time typically belongs on the x-axis due to its role as an independent variable in time-dependent processes. The user seeks clarification on these graphing conventions and the implications for their upcoming exam.
tommyleehutch
Messages
8
Reaction score
0
physics resit soon! help please! a VERY simple graph problem

This is physics from the last year of high school. So think of me as being about 17ish or 18ish.

The exam/test thing is for uncertainty. It will involve graphs.I have to express one thing from a graph in terms of another involving the gradient.
One of the two quantities will be squared or rooted or 1/x or 1/x^2.

question 1 (the important one!)

This here is an answer ( I don't have the question ).
I'm sure the question would have read something like:
"show the link between frequency and time period"
(((the answer, its correct btw!))
F^2= (43 +- 3) T
(or)
f = (6.6 +- 0.3) sqroot T

43 and 6.6 are the gradients. 3 and 0.3 are the uncertainties. (note that 0.3 was rounded from 0.23)
Only one of those is needed its just when you graph the data in the exam you have the choice of how to graph it.
One is from a F^2 against T graph and the other from a F against sqroot T graph.
I'm guessing the answer from above must be about a pendulum or something. lolMy problem is I don't know which way to graph it.
For example if I got that exact question tommorrow what is to stop me from expressing the answer as T = (43 +- 3)f^2 [as opposed to the correct answer F^2= (43 +- 3) T]
?
thats the thing for me.
I don't know if the axis is important?
I'm guessing it is, but actually I don't remember the question so I don't know which quantity was y-axis and which one was x axis. So I can't even check that to tell you...anyway that there is a lot of info, perhaps even too much, please post and let me know if something needs clarify. I'm more than happy to. :D!I really need that but also I have 2 more questions related to my exam.

rounding: if i get uncertainty (absolute) for example 55.5 +- 1.32456787654345678
and i want to round it... should it become 55.5 +- 1.3 or 55.5 +- 1.4
you could round it down just like you normall would do when rounding.
however you might want to round it up to increase its uncertainty.
hmm?time's axis: I heard that independent on x and dependent on y.
However there is exception that if time is involved it always go on x.
However I'm just wondering is there an exception that could actually have time placed on the y axis?
 
Physics news on Phys.org


About graphing, think of it like this: Put the independent measure on x-axis and the one that depends on it on y-axis. Time always goes on x-axis because all the processes that involve time, are time-dependent. Can you think of anything on which time is dependent? I don't think so.

For example, if you have an object moving with constant acceleration, than it's velocity is time-dependent. If you wanted to graph it's velocity equation, than time would go on x-axis and velocity on y-axis, where from the graph we can see that the more time has passed, the more the velocity has increased.
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...

Similar threads

Back
Top