STPM Term 3, Day 1

It's the last term, and the last paper for every subject.

It starts with Physics as the first paper. Unlike previous years where it would begin with PA, this year they decided to break the trend and put Physics as the first paper. The reason I could think off is probably because now, they wanna complete all papers in four days, hence the put several papers together in one slot. This might cause some people to have two papers at the same time (paper crashing), and to minimise such problem they have put PA to the 2nd day, and Physics to the first slot on the first day, together with Bahasa Arab.

Anyway, Physics paper 3 was downright ridiculous. The objective questions were fine, structured were a bit unexpected but you could do your best to come out with plausible answers. Essay questions were the toughest one. First of all, it tested us on topics we never found important because it was too hard, and it came out with a question that required a trigonometry formulae we learnt only in the first term. After a year I believe most have forgotten it.

And, like every STPM papers, the pattern of the question is new and not previously found. Basically, for STPM, past year questions aren't really helpful because the questions don't usually repeat themselves and the lecturers present their questions differently every year. This year it definitely is something quite new, and I really got a shock when I saw the questions.

Well, what can I say? This is STPM. The third term exam began with a sense of foreboding, as it has appeared to be.

Just in case you're curious about the essay questions, I'll show you two of the three questions:

18) 
(a)        i.  What is meant by a transverse wave?
           ii.  Distinguish between a transverse wave and a longitudinal wave.

(b) The periodic motion of a particle at the left end of a stretched string is defined by

y = 6.0 sin pi t

where y is in centimetres and t in seconds. The wave disturbance travels along the string at a rate of 6.0cm per second. 

(i)    Derive an expression for the displacement of a second particle on the string at point x to the right of the first particle at a later time t.

(ii)   Determine the displacement of the second particle is x is 80cm and t is 1 minute.

(c) A transverse wave is given by

       y = 6.0 sin pi(4.0t + 0.020x)

where x and y are in centimetres and t in seconds.
(i)   Determine the speed of the wave.
(ii)  Determine the maximum transverse wave of a particle of the wave.
(iii) Sketch the shape of the wave when t is 0.125s.


20)
(a) Explain the terms "energy levels" in an atom, and state the reason for its negative signs.

(b) Explain what do you understand by
     (i)    the ionisation energy of an atom,
     (ii)   the occurrence of a line spectrum

(c) A hydrogen atom in its second excited state undergoes a transition to the ground state by emitting photons. Determine the possible wavelengths of the emitted photos.

(d) A hydrogen atom is excited with its electrons in the energy level n = 4. Determine the energy, in eV, that is require to ionise it.

(e) An electron with energy 1.80 x 10^-18 J collides with a hydrogen atom in its ground state and the electron is deflected. If the hydrogen atom is excited with its electron in the energy level n = 2, determine the energy of the deflected electron.