Physics: Post your doubts here!

[areeba240]

helppppppppppppp plzzzzzzzzzz
thanks in advance

 

[The Sarcastic Retard]

Hello guys, I have a paper in 6 hours (School terminals).
I got 78 in paper 4. I am tensed about paper 5 coz I hardly get 18 in it.
This is my average score. I want over all A grade in my As and A level result.
I have 76% (b) in my As level result, will I be able to get an A with the marks I mentioned above (I am giving my A level paper 4 and 5 in this November session) or should I increase my marks?

Really I will be appreciating if I got some notes on apparatus used in particular experiment in paper 5 Q1s.
I can score good in Q2 but Q1 I end up getting 5 or 6. That's it!

Thank you. ^_^

 

[Rizwan Javed]

View attachment 60074
helppppppppppppp plzzzzzzzzzz
thanks in advance

I think you need to consider the position of center of gravity here and then calculate the change in gpe of the block. The position of center of gravity, is 1.1m above the ground initially. After knocking over, the final height from the ground is 0.2m.
So the the change can be calculated this way:

Ep = 500 * (0.2-1.1)
= -450 J (the negative sign here indicates a loss of energy, you can ignore it since you're interested in finding the magnitude as energy is scalar)

So change in Ep is 450J.

The answer is C.

 

[areeba240]

helpppppppp plzzzzzzzzzzzzz
thanks in advance

 

[areeba240]

helpppppppp plzzzzzzzzzzzz
thanks in advance

 

[areeba240]

helpppppppp plzzzzzzzzz
thanks in advance

 

[ashcull14]

Hello guys, I have a paper in 6 hours (School terminals).
I got 78 in paper 4. I am tensed about paper 5 coz I hardly get 18 in it.
This is my average score. I want over all A grade in my As and A level result.
I have 76% (b) in my As level result, will I be able to get an A with the marks I mentioned above (I am giving my A level paper 4 and 5 in this November session) or should I increase my marks?

Really I will be appreciating if I got some notes on apparatus used in particular experiment in paper 5 Q1s.
I can score good in Q2 but Q1 I end up getting 5 or 6. That's it!

Thank you. ^_^

try this link
https://docs.google.com/folderview?id=0Bx_kNsO4S1YbTEZYb09ucmVLOEE&usp=docslist_api

 

[ashcull14]

 

[ashcull14]

 

[ashcull14]

is it necessary for worst fit line to cross the best fit or can it remain parallel to it throughout?

 

[The Sarcastic Retard]

is it necessary for worst fit line to cross the best fit or can it remain parallel to it throughout?

Till now my every experiment W.F cut the B.F. Thanks for the link, hope so that is useful.
So can I stretch it to A?

 

[ashcull14]

Hello guys, I have a paper in 6 hours (School terminals).
I got 78 in paper 4. I am tensed about paper 5 coz I hardly get 18 in it.
This is my average score. I want over all A grade in my As and A level result.
I have 76% (b) in my As level result, will I be able to get an A with the marks I mentioned above (I am giving my A level paper 4 and 5 in this November session) or should I increase my marks?

Really I will be appreciating if I got some notes on apparatus used in particular experiment in paper 5 Q1s.
I can score good in Q2 but Q1 I end up getting 5 or 6. That's it!

Thank you. ^_^

78 is a good score
it means that u can do even better in paper 5 by practicing
give it further more attempts and recheck ure score
hope ure done wid all the pastpapers
percentile for paper 5 is usually quite low
depends on ure score in AS ,,,on what percentage was it a B grade?
if it was 76 above ..well and good
So hopefully there r chances of achieving an A grade

 

[sj0007]

View attachment 60076
helpppppppp plzzzzzzzzzzzzz
thanks in advance

In this question, to find the effect of w, u would have to make an expression relating stress and w
Stress = force/area
The area over here is the area of the thin metal, the one that has the thickness of w. So, imagine cutting the cylinder in a way that it forms a cuboid with the thin area being a rectangle at the side. Now, the area would be: Circumference of the hollow cylinder (length)*w(width) = pi*d*w
This expression shows how w is proportional to the area
And since the area is inversely proportional to stress, 2w would give u half of the stress
Hope u understand

Oh and do u know about the site: physics-ref.blogspot.com? It's really amazing incase u have doubts which u want to get cleared right away. Just type the question (the first sentence) and google it, u will get this site as a result (if there is an explanation of that doubt). Most of the questions are solved

 

[The Sarcastic Retard]

78 is a good score
it means that u can do even better in paper 5 by practicing
give it further more attempts and recheck ure score
hope ure done wid all the pastpapers
percentile for paper 5 is usually quite low
depends on ure score in AS ,,,on what percentage was it a B grade?
if it was 76 above ..well and good
So hopefully there r chances of achieving an A grade

I got 76% in As level. Hope so I end up getting an A. ^_^ Thanks.

 

[Shah34]

Any tips on phy mcqs like questions posted above there sooooooo hard? How do you tackle these type of qs???

 

[Xylferion]

View attachment 60085

That's a comparator circuit, which basically means that you get an output after comparing the two inputs.

If V+ > V-, you get +5V as your output.
If V- > V+, you get -5V as your output.

They tell you that non-inverting input is at a fixed 1.0V.
That means, for values >1.0V, the output is -5V and for values <1.0V the output is +5V.

You can already see on the graph that it starts of at 2V and continues till it crosses 1V. For this entire duration, V- > V+, so the output = -5V.
Next, you can see that it goes from 1V to 0V and then back to 1V. For this duration, V+ > V-, so the output = +5v.

Hope any of that made sense, if not just reply to this and I'll try to explain it better.

 

[The Sarcastic Retard]

9702_s10_qp_43
Q1b(iii)
Q8(b)

 

[pundadesh]

9702/22/M/J/11 Q2(b)(ii)

A second raindrop has a radius that is smaller than that given in (a). On Fig 2.1, sketch the variation of speed with time for this second raindrop

The sketch is below the original curve

Is it because the radius is smaller therefore the mass is smaller as well (since p=mv) so it reaches terminal velocity earlier?

 

[ashcull14]

That's a comparator circuit, which basically means that you get an output after comparing the two inputs.

If V+ > V-, you get +5V as your output.
If V- > V+, you get -5V as your output.

They tell you that non-inverting input is at a fixed 1.0V.
That means, for values >1.0V, the output is -5V and for values <1.0V the output is +5V.

You can already see on the graph that it starts of at 2V and continues till it crosses 1V. For this entire duration, V- > V+, so the output = -5V.well expl
Next, you can see that it goes from 1V to 0V and then back to 1V. For this duration, V+ > V-, so the output = +5v.

Hope any of that made sense, if not just reply to this and I'll try to explain it better.

well explained thanks a lot

 

[Aishayasin]

PART Bi