Physics: Post your doubts here!

[farhan143]

A sphere of radius R is moving through a fluid with a constant speed V. There is a frictional F acting on the sphere.
F=6(pie)DRv.
Where D depends on the fluid.
a) Show that the SI base units of D are kg(m^-1)(s^-2) OR kg/ms^s .
b) A rain drop of radius 1.5mm falls vertically in air at a velocity of 3.7m/s . The value of D for air is 6.6 x 10^-4 kgm^-1s. The density of water is 1000kg/m^3.
(i) Calculate the magnitude of the frictional force F.
(ii) Find the acceleration of the rain drop.



CAN ANYONE GIVE ME A LINK FOR ONLINE VIDEO TUTORIALS FOR PHYSICS, JUST LIKE THE ONE FOR MATHS IT IS VERY HELPFUL IN UNDERSTANDING AND
PLEASE SOLVE THIS QUESTION FOR ME THANK YOU!

 

[larina]

PAPER 5!!!
almost on every recent papers they are asking to write the absolute errors
1)how to find absolute errors?
2)how to make a worst acceptable straight line on a graph?
3)how to include errors in the gradient or the y-intercept?


Will be waiting for an answer soon inshaAllah, thanks

 

[larina]

PAPER 5!!!
almost on every recent papers they are asking to write the absolute errors
1)how to find absolute errors?
2)how to make a worst acceptable straight line on a graph?
3)how to include errors in the gradient or the y-intercept?


Will be waiting for an answer soon inshaAllah, thanks

 

[unique840]

A sphere of radius R is moving through a fluid with a constant speed V. There is a frictional F acting on the sphere.
F=6(pie)DRv.
Where D depends on the fluid.
a) Show that the SI base units of D are kg(m^-1)(s^-2) OR kg/ms^s .
b) A rain drop of radius 1.5mm falls vertically in air at a velocity of 3.7m/s . The value of D for air is 6.6 x 10^-4 kgm^-1s. The density of water is 1000kg/m^3.
(i) Calculate the magnitude of the frictional force F.
(ii) Find the acceleration of the rain drop.



CAN ANYONE GIVE ME A LINK FOR ONLINE VIDEO TUTORIALS FOR PHYSICS, JUST LIKE THE ONE FOR MATHS IT IS VERY HELPFUL IN UNDERSTANDING AND
PLEASE SOLVE THIS QUESTION FOR ME THANK YOU!

a) newton=D*metre*metre/second
newton = kgm/(s^2)
d*m*m/s = kgm/(s^2)
d=kg(m^-1)(s^-2)

b)i) f = 6(pie) * 6.6 x 10^-4 * 1.5 x 10^-3 * 3.7
f = 6.9 x 10^-5

ii) f = ma
f = 6.9 x 10^-5
m = density*volume
m = 1000*[(4*pie*r^3)/3]
m = 1.4 x 10^-5
a = 4.88 m/s^2

 

[omg]

you should post the questions over here in which you are facing difficulties or have problems solving them.

im havin problems in it as a whole!
is there any site or sth with p5 help??

 

[CaptainDanger]

im havin problems in it as a whole!
is there any site or sth with p5 help??

A Level Physics Paper 5 Tips

 

[omg]

A Level Physics Paper 5 Tips

im havin problems in log!! when to draw the log graph?? and how to find the uncertanity???

 

[CaptainDanger]

im havin problems in log!! when to draw the log graph?? and how to find the uncertanity???

Uncertainties

* % Uncertainty =
* When multiplying or dividing quantities, add their % uncertainties together.
* When adding or subtracting quantities, add their absolute errors together, then divide by the result of the addition/subtraction of the measurement, e.g. for , where , and , the absolute errors added = 0.102 mm. Therefore the % uncertainty is:
* If you have to calculate the error in, e.g. , the absolute error in d must be multiplied by pi and then added to the absolute error in x. The percentage uncertainty is this total error divided by the calculated and the result multiplied by 100.
* If a measurement is to be raised to a power, then multiply the % uncertainty in the measurement by the power to get the % uncertainty in the overall term.
* If two values, for say, a density are available, calculate the % difference between them. If a value is given by the examiner, then use this as the "correct" value, and calculate the % difference the following way: where x is your measured value, and c is the examiner's value. If you have obtained two values, then the expression changes: where x1 and x2 are your measured values, and is the median of the two, (not necessarily the mean!).
* Compare the % difference with your % uncertainty. Any relationship suggested, such as that the two densities should be equal, can be considered correct if your % difference is less than your % uncertainty. This will gain you marks!
* If your % uncertainties look small, check that you have multiplied by 100!

 

[hassam]

http://www.xtremepapers.com/CIE/International A And AS Level/9702 - Physics/9702_w06_qp_4.pdf
markscheme says increase amount of damping without alteration of spring constant(k) or mass(m).......bt how cn we increase amount of damping otherwiSeQ3.part (c)

 

[omg]

Uncertainties

* % Uncertainty =
* When multiplying or dividing quantities, add their % uncertainties together.
* When adding or subtracting quantities, add their absolute errors together, then divide by the result of the addition/subtraction of the measurement, e.g. for , where , and , the absolute errors added = 0.102 mm. Therefore the % uncertainty is:
* If you have to calculate the error in, e.g. , the absolute error in d must be multiplied by pi and then added to the absolute error in x. The percentage uncertainty is this total error divided by the calculated and the result multiplied by 100.
* If a measurement is to be raised to a power, then multiply the % uncertainty in the measurement by the power to get the % uncertainty in the overall term.
* If two values, for say, a density are available, calculate the % difference between them. If a value is given by the examiner, then use this as the "correct" value, and calculate the % difference the following way: where x is your measured value, and c is the examiner's value. If you have obtained two values, then the expression changes: where x1 and x2 are your measured values, and is the median of the two, (not necessarily the mean!).
* Compare the % difference with your % uncertainty. Any relationship suggested, such as that the two densities should be equal, can be considered correct if your % difference is less than your % uncertainty. This will gain you marks!
* If your % uncertainties look small, check that you have multiplied by 100!

i think sm text is missing?? :/

 

[CaptainDanger]

i think sm text is missing?? :/

Yeah I guess... But its what I got everywhere...

 

[omg]

Yeah I guess... But its what I got everywhere...

can u give me the source of this material??

 

[farhan143]

a) newton=D*metre*metre/second
newton = kgm/(s^2)
d*m*m/s = kgm/(s^2)
d=kg(m^-1)(s^-2)

b)i) f = 6(pie) * 6.6 x 10^-4 * 1.5 x 10^-3 * 3.7
f = 6.9 x 10^-5

ii) f = ma
f = 6.9 x 10^-5
m = density*volume
m = 1000*[(4*pie*r^3)/3]
m = 1.4 x 10^-5
a = 4.88 m/s^2

How do i know whether the volume of a rain drop is spherical or a (cone + hemishphere)???
but thank you for clearing it out

 

[farhan143]

Another question i have doubt

An ion is acclelerated by a serires of electrodes in a vacuum. a graph of the power supplied to ion is plotted with time. What is represented by the area under the graph between two of them?

please post a link for online physics tutorials for different as chapter.............
Thank you.......

 

[abcde]

Another question i have doubt

An ion is acclelerated by a serires of electrodes in a vacuum. a graph of the power supplied to ion is plotted with time. What is represented by the area under the graph between two of them?

please post a link for online physics tutorials for different as chapter.............
Thank you.......

The energy supplied during that time.
For video tutorials, you may visit khanacademy.org
http://www.thestudentroom.co.uk/wiki/Revision:Physics_Formulae_(OCR_A_Level)
http://www.miniphysics.com/2010/11/measurement.html
http://www.s-cool.co.uk/a-level/physics/units-quantities-and-measurements

 

[farhan143]

The energy supplied during that time.

Well what type of energy supplied is it kinetic or potential

 

[Nibz]

Well what type of energy supplied is it kinetic or potential

There is 'Motion' involved so it's kinetic energy.

 

[farhan143]

thank you!!
very much a site with gud teachers on whum i can rely on

May ALLAH bless this site and the students those whu are clearing doubts so well!!

 

[abcde]

It is the total energy supplied during that time.

 

[CaptainDanger]

can u give me the source of this material??

Some user posted it here...