13.1b Ex4 MJ19 P42 Q1 Gravitational Torque | A2 G-fields | Cambridge A Level 9702 Physics

[@HAPPYDIA4U]

thank you

[@ummehabeehafatima]

It was really helpful, Thank you😊

[@maaziakashif6248]

why can't we say that air resistance can affect the result, in the last part?

[@danishqureshi2]

"Candidates found this question difficult. Many candidates missed the fact that the question was asking about the force between the spheres, not about other forces that may be exerted on each sphere individually. Common responses that were not awarded credit referred to air resistance (the system is static), torsion in the thread (already in consideration), and gravitational attraction to the Earth (not a force between the spheres). These responses illustrate the importance of reading the question carefully and answering the question that is asked." This is what the examiner report says.

[@saviaidres1800]

So ms for question C (i), my teacher said I would not get the mark for having gotten 6.5 x10^-11 instead of 6.4 x10^-11, even if I show my substitution clearly. but Ms one problem I come across is. It's really confusing each past paper is different, sometimes they use rounded or calculator value and both give different values. What do I do then? How would I know which to use?

[@danishqureshi2]

I think the right way is to use rounded values for the final answer and use calculated values for further calculations. For this question, if we use 1.395 x 10^-11 as calculated for torque in further calculation then we get 6.44 x 10^-11 which can be rounded off to 6.4 x 10^-11.

[@ayoo9963]

Thank youu