hi,

this is a test to see how much attention you paid in physics class.

Link here



I'll go first. 88 points

F.A

Question 20 is ambiguous, but perhaps only to those whose physics training is more academic.

Question 38 is ambiguous, and 39 contains a grammatical error.

The wording of 41 is physically incorrect.

I got 88 as well. I am reviewing my answers. I would fail the examiners in their failure to appreciate precision in the language of physics. It seems to me that they were dozing in physics class, or they had poor teachers. I am writing a critique. But it may spoil the questions for others, if they want to try it, so I will refrain from publishing it just yet. Are the questions chosen at random from a larger set of problems in this online test? Or are the questions the same for everyone? It looks the same having tried it again.

Question 8 was ambiguous, as the differences between the terms turn and rotate are arbitrary. In fact, in astronomical language, the planet gears will be said to rotate counter clockwise and revolve clockwise. And as the planetary gear is obviously described in astronomical terms, the planet gears are most accurately said to be revolving about the sun gear and rotating in the opposite direction. I chose the first answer that would fit. Even though it did not meet the requirements of the test, I had the correct mental picture of the motion of the gears and I maintain that the answer I chose was a correct verbal description. There is no objective distinction between answers B and C to this question.

Question 45 about balloons is plain wrong. Atmospheric pressure is a constant for all the balloons. The examiners confuse the concepts, or at least the labels, of pressure and force in this question and in question 41. The balloons experience a force exerted by the atmosphere in proportion to their surface areas, but the pressure--the force per unit area--they experience is the same.

Question 48 is arbitrary with two correct answers. The motion of the piston downwards lowers the pressure in the cylinder and the outside air is drawn in because it is at a greater pressure. So you could say equally that it is suction because of the downward motion of the piston and atmospheric pressure causing it. Therefore you can only guess at the answer.

I said question 20 is ambiguous because although the answer it is looking for is stable it is actually unstable. It is more accurate to say that it is in equilibrium, but it is in a class of equilibria known as unstable equilibria, as the slightest unbalanced force will start it moving and it won't return to the equilibrium. Stable equilibria are ones in which the the system will return to its state of equilibrium once any disturbing influence is removed.

Question 38 is ambiguous because "same direction" and "opposite direction" have no clear meaning here.

Question 39 should read "principle" instead of "principal".

Andrew Andrew Andrew, deary me. Academics, they just dont get it do they....Joking hehe
I got 88 also. The pully questions failed me i think.

Out of interest, my 12 year old got 60, but he said he didnt understand any of the electrical questions as he has never done cct theory.

The questions I got "wrong" were the planetary gear one, the balloon one and the one about air intake in a cylinder. I got the one about opposing fans right, but that was really a guess, I assumed they meant with reference to the room.

The ones I got properly wrong were the one about flammable substances--I thought gasoline was more difficult to ignite than diesel, which is aparently not true--I got wrong the question on identifying electrical symbols, as they are not the same as what I am used to. These might be familiar to automotive technicians, but in electronic engineering and physics they are different. The symbols for the fuse and load I did not recognize. The fuse symbol lookes most intuitively like a "load" symbol to me and the load symbol looked most intuitively like a "fuse" symbol. I also got wrong the one about the flow of water through a pipe. I thought the pressure would be greatest in the constriction. And really I should know the answer and not just guess.