IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: cs on June 11, 2010, 04:34:12 am

Title: Physics Practical
Post by: cs on June 11, 2010, 04:34:12 am: In parts of Practical paper. e.g paper 31 of June 2007
the question asked "it is suggested that h is directly proportional to xsquare. Do the results of your experiment support this idea? You should explain your reasoning clearly."
What actually do i need to do?
Title: Re: Physics Practical
Post by: Vin on August 24, 2010, 08:00:13 pm: You see if your results match the statement.
How?

They've said h $\propto$ x². So you get rid of the proportionality sign by adding a constant k.
Therefore, h = k.x²

Substitute values of h and x² to find k.
Do this for all your readings.

If you have a greater difference, suppose for eg. k1 = 4890 , k2= 3240. So this definitely is not proportional hence statement is incorrect.

If you have a smaller/equal difference, for eg. k1 = 4890, k2 = 4820. Then statement is true.

Sorry for the late reply By the way. :P Just noticed. ::)
Title: Re: Physics Practical
Post by: Deadly_king on August 25, 2010, 11:30:57 am: sometimes you are asked to carry out the experiment only 2 times such that u have only 2 readings.

Then u should calculate your constant K using the two readings.

Find out a mean value for K.............k=(K₁+K₂)/2

Then (K₁-K₂)/K * 100..............if the value is less than 20.......then we can deduce that h is proportional to x. Otherwise it is not the case.
Title: Re: Physics Practical
Post by: cs on August 29, 2010, 07:08:59 am: Thanks!! not too late.. :)
Title: Re: Physics Practical
Post by: Deadly_king on August 29, 2010, 08:01:29 am: anytime br0...:)