Edexcel PHYSICS Doubts

[T.Q]

how much was the work done in the tension question

i used this equ.

 i dont remember the distance

[Saladin]

how much was the work done in the tension question

i used this equ.

 i dont remember the distance

Dunno about that. I equated like finding the value of T through sin and cos values, to find a tan value.

And used that tan value to calculate tension.

[T.Q]

Dunno about that. I equated like finding the value of T through sin and cos values, to find a tan value.

And used that tan value to calculate tension.

ya i know , but im talking about the workdone question  (next part)

after the tension and angel part

[Saladin]

ya i know , but im talking about the workdone question  (next part)

after the tension and angel part

thats easy, you just simply multiply the tension by the distance moved.

because the girl is the source of tension.

[T.Q]

thats easy, you just simply multiply the tension by the distance moved.

because the girl is the source of tension.

ya , but u had to multiply force with cos theta

because the force is not in same direction of motion

[Saladin]

ya , but u had to multiply force with cos theta

because the force is not in same direction of motion

yes, but it is force moved into the direction of force, the only force she is applying is the tension.

And she is acting in the opposite direction to it.

[student]

A question from A2 ActiveBook.


(A note on the graph from the book.)

If this were a model of an automatic hand dryer circuit which requires 4.0V to operate, use the graph to work out for how long it will remain on.

The spreadsheet says the time constant is 20s, and thats what I could read off the graph.
But aint time constant = RC? And RC is 200*0.0001=0.02s, not 20s..

So.. As the minimum required voltage is 4V it won't work below that? And initial is 6V:

V = V₀e^-t/RC
V/V₀ = e^-t/20
20 ln(4/6) = -t
t = 8.109s
Wrong..
And using a lower RC would only give a shorter time, but it's 50s+.

[Saladin]

A question from A2 ActiveBook.


(A note on the graph from the book.)

If this were a model of an automatic hand dryer circuit which requires 4.0V to operate, use the graph to work out for how long it will remain on.

The spreadsheet says the time constant is 20s, and thats what I could read off the graph.
But aint time constant = RC? And RC is 200*0.0001=0.02s, not 20s..

So.. As the minimum required voltage is 4V it won't work below that? And initial is 6V:

V = V₀e^-t/RC
V/V₀ = e^-t/20
20 ln(4/6) = -t
t = 8.109s
Wrong..
And using a lower RC would only give a shorter time, but it's 50s+.

I regret not having the ability to answer that question. I have not finished my AS yet. I am deeply sorry.

[seth99]

hey this is my frirst question on this forum.
I have A levels physics paper 5 on 9th , i have problem answering first question. if you could tell me where do i add the additional details? shall i make it as another subheading and write all additional details(as answerd in mark scheme) or shall i keep adding in the subheadings i give while answering the question.
Answer to the question number 1 is in this format given in mark scheme.
Defining the problems
Methods of data collection
Annalysing the data
safety precautions
ADDITIONAL DETAILS

[Saladin]

hey this is my frirst question on this forum.
I have A levels physics paper 5 on 9th , i have problem answering first question. if you could tell me where do i add the additional details? shall i make it as another subheading and write all additional details(as answerd in mark scheme) or shall i keep adding in the subheadings i give while answering the question.
Answer to the question number 1 is in this format given in mark scheme.
Defining the problems
Methods of data collection
Annalysing the data
safety precautions
ADDITIONAL DETAILS

Just post your doubt here!

[nid404]

Just post your doubt here!

That sounds out of place

Please post your doubts here 

[Saladin]

That sounds out of place

Please post your doubts here 

Wait let me add some effects.

[Saladin]

You may simply post them here.

[Saladin]

hey this is my frirst question on this forum.
I have A levels physics paper 5 on 9th , i have problem answering first question. if you could tell me where do i add the additional details? shall i make it as another subheading and write all additional details(as answerd in mark scheme) or shall i keep adding in the subheadings i give while answering the question.
Answer to the question number 1 is in this format given in mark scheme.
Defining the problems
Methods of data collection
Annalysing the data
safety precautions
ADDITIONAL DETAILS

Just one problem, what is the question?

[seth99]

well in a levels physics paper 5(planning,Annalysis and evaluation) we have only 2 questions to answer. format for question number can be seen on any of the previous years question paper
http://www.xtremepapers.net/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_s07_qp_5.pdf