ICSE − Q & A

in this question
A man having a box in head climbs a slope and another man  having an identical box walks the same distance on a levelled road.Who does more work against the force of gravity and why?
why everyone is concluding that the work in 2 case is zero.
is it not possible that the man is pushing the box on the road for causing displacement ??????

https://www.respaper.com/vsharp/435/432/4224-pdf.html how to solve and what is formula 6 and 7

+ 1 more questions by pavithran5  

https://www.respaper.com/dhrumij1506/4240-zip.html any one answer question 1 C
asked by T.M.Devi T.M (pavithran5) 5 years ago
1

Can they ask us to draw diagrams from any other chapter other than light?

The UCM acceleration "confusion" :

Honestly, I am baffled. I know for sure that the acceleration is non-uniform, and I'll give you a valid reason for that, but then even @shauns has made a valid argument. If you care to look at Q 5 a(ii) of ICSE 2016, they have asked "Is the acceleration uniform?", and in the Pupil's Analysis marking scheme, they have answered "Yes".

I really don't understand the mysterious logic they have applied here. I think, in this case of confusion, you should go by whatever your Selina says. The only plausible logic behind their strange answer can be that by "uniform" they imply that the magnitude is constant. I really am not sure though.

However, in actual "non-confusing" terms, the acceleration in UCM is variable. Reason is short and precise: the magnitude of the acceleration is constant, the direction is not. 

Now if you think that the direction is also uniformly changing, you're wrong, because we don't talk of "change in magnitude" and "change in direction" separately when dealing with vectors.

For eg, consider a particle in UCM, and note its acceleration vector at one point. Let us assume that it is 4 m/s^2, towards the left. Now, when the particle reaches the diametrically opposite point, its acceleration will be 4 m/s^2, towards the right. Now, if you have any knowledge of vectors, you will understand that when you subtract these two vectors, it would be -8 i cap.

To explain this simply, it is as if the acceleration at the first point that I mentioned is -4 and the acceleration at the diametrically opposite point is +4, so when you subtract +4 from -4 to calculate change, it is -4 - (+4) = -8.

Thus, there is clearly a change in the acceleration vector, so acceleration is not constant. 

But this still doesn't answer the burning question : What the hell do we write in the paper?

I think you should stand with logic, and answer "No, because the magnitude is constant, but the direction is changing as when the particle moves in a circle, the vector towards the center changes in direction."

I think that if you give a correct reason, it will remove any scope for doubt. 

In the end though, it is all up to your prudence. If you want to go with the 2016 answer, your choice. If you don't, it's again your choice.

I don't know how the board thinks, so in any case, I am not in a position to tell you what they will accept as correct. I can only tell you what I know is correct as per logic. If you didn't get what I'm trying to hint at subtly, these last two lines are a sort of disclaimer. Please be advised :P.

ATB, see you later.

https://m.timesofindia.com/home/education/news/history-teachers-allege-mistakes-in-icse-question-paper/amp_articleshow/68231390.cms

In ICSE 2016

A stone of mass m is rotated in a circular path with a uniform speed by tying a strong string with the help of your hand answer the following questions:

Q5 a) ii) Is the stone moving with a uniform acceleration in which direction does the acceleration act? 

IN ALL THE BOARD QUESTION ANSWER TEXTBOOKS THE ANSWER GIVEN IS YES IT IS A UNIFORM ACCELERATION... IN THE TEXTBOOK IT IS GIVEN ITS A VARIABLE ACCELERATION. HOW!?! 👿

Why is earth pin longer than the other two pins!??

A flag is made up of three strips of cloth of yellow, white and cyan colours. Name the colour of a particular light in which this flag will appear to be of a single colour.

+ 2 more questions by krishnair  

Explain why in daylight an object appear red when seen through a red glass and black when seen through a blue glass?
asked by Krish Rajiv Nair (krishnair) 5 years ago
0

When yellow paint and blue paint are mixed we get a green colour. When yellow light and blue light are mixed, white light is obtained. Give reasons.
asked by Krish Rajiv Nair (krishnair) 5 years ago
0

i wrote bhramo instead of brahmo - any hope of marks

+ 1 more questions by teleansh  

Should we learn speed and mass of alpha beta gamma
asked by Ansh Anand (teleansh) 5 years ago
0

Guys just to share a fact that in lens diagrams 
Remember we have to erase those extra lines after intersection of light rays else  a hollow image will be formed (this is an error given in Selina book)