Physics: Post your doubts here!

[Abhishek Neogi]

hey guys plz help me out with ques 9
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_11.pdf

The Ans is Option D
That's because in free fall the rate of acceleration increases for the ball since the force of gravity is acting on it.
Besides,they've stated that it starts from rest.[From the origin that is]
Plot the same distance time graph as a velocity-time graph and you'll see what I mean.

You need to know the difference between displacement-time,distance-time,velocity-time and acceleration-time graphs in order to solve these types of questions.

 

[Yousif Mukkhtar]

Can some one explain to me 2 c)
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_23.pdf

 

[Yousif Mukkhtar]

Resolve v :
1. You get v cos theta along X . So magnitude of X = v cos theta
But using mathematical knowledge :
Increasing theta form 0 to 90 degrees causes cos theta to decrease . Remember the graph for cos theta ? Do refer to it.
Hence along X , v cos theta decreases, so X decreases.

2. You get v sin theta along Y .So magnitude of Y = v sin theta .
But again applying mathematics:
Increasing theta from 0 to 90 degrees causes sin theta to increase . Refer graph of sin theta .
Hence Y increases.

Hope it helped!

Thanks mate.

 

[Abhishek Neogi]

When a ball is dropped and allowed to fall under free gravity it will have three different stages- initially the resistance will greatly oppose the body, so the displacement/time graph would NOT be too steep but would (obviously) have a negative gradient. Then eventually, the ball will reach terminal velocity, where acceleration is 0 and the speed is constant, so you will get a straight line with a negative gradient. Then, finally will come a point where when the downward force will be much greater than the resistance (when it gets closer to the ground), hence the graph will be VERY steep.

From the description you can tell the answer is B.

Hey hey!But doesn't Ans B denote negative acceleration [aka retardation] ?!
I mean if you convert that h-t graph to a velocity time graph then it does make sense!
I think it should be Ans. D
And the gradient's only negative when a ball is thrown upwards [opposing the force of gravity as a result] -_-

 

[Ahmed Khider]

Could anyone explain to me how to solve this question briefly??
Thanx in advance...

Anyone???

 

[eyamwir]

salam everyone i need help. i'll just post the link here. please go to this page and help me do this assignment. i'm a bit lost ://
http://www.xtremepapers.com/communi...-needed-on-basic-electronic-principles.20078/

 

[Beca1206]

Hey Guys!
I'm in desperate need of someone's help! Can anyone post May/June 2002 past paper and the mark scheme
Please Please i need it for Tommorrow and didnt realise its not available on the website... anyone got it??

 

[queen of the legend]

may/june 2003 , paper1 , question : 5, 11, 17, 19, 22, nd q.40


please help!

 

[VelaneDeBeaute]

may/june 2003 , paper1 , question : 5, 11, 17, 19, 22, nd q.40


please help!

Link! Link!?

 

[yumichikabyakuya renji]

Link! Link!?

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s03_qp_1.pdf

 

[yumichikabyakuya renji]

Hey Guys!
I'm in desperate need of someone's help! Can anyone post May/June 2002 past paper and the mark scheme
Please Please i need it for Tommorrow and didnt realise its not available on the website... anyone got it??

 

[yumichikabyakuya renji]

here u r

 

[yumichikabyakuya renji]

Hey Guys!
I'm in desperate need of someone's help! Can anyone post May/June 2002 past paper and the mark scheme
Please Please i need it for Tommorrow and didnt realise its not available on the website... anyone got it??

i d0nt hav the ms for p1

 

[Soldier313]

i d0nt hav the ms for p1

Hey Guys!
I'm in desperate need of someone's help! Can anyone post May/June 2002 past paper and the mark scheme
Please Please i need it for Tommorrow and didnt realise its not available on the website... anyone got it??

here's the ms for p1 for mj/02 physics

 

[yumichikabyakuya renji]

here's the ms for p1 for mj/02 physics

View attachment 16140

did u work out jun 2011? cud u help me out with q2? N i didn't get what is the difference between quantity and unit

 

[yumichikabyakuya renji]

hey guys can u help me out with jun 11?? i had lots of problem with
2, 20, 25, 35

and for the second variant:
Q2
Q3 why is the answer not D?
and Q9

 

[Albert Einstein]

Post z question directly- Make a print screen

 

[Soldier313]

did u work out jun 2011? cud u help me out with q2? N i didn't get what is the difference between quantity and unit

Hey i am done with AS am in A2 now
but yea i sure can help
look....quantities are like mass, length, time
their units are kilograms, metres, seconds
so basically in the qn u asked, the qn wants quantities not units
so option A - ruled out coz it has 'metre' ( which is a unit)
option B - the statement itself is wrong, pd is not equal to energy per unit current
option C - the correct answer since it is the right definition and uses only quantities
option D - ruled out coz it has 'second' (which is a unit)

hope that helped....

 

[yumichikabyakuya renji]

Hey i am done with AS am in A2 now
but yea i sure can help
look....quantities are like mass, length, time
their units are kilograms, metres, seconds
so basically in the qn u asked, the qn wants quantities not units
so option A - ruled out coz it has 'metre' ( which is a unit)
option B - the statement itself is wrong, pd is not equal to energy per unit current
option C - the correct answer since it is the right definition and uses only quantities
option D - ruled out coz it has 'second' (which is a unit)

hope that helped....

hmmm, for A, B and D it certainly helped
bt wat i still don't get is why area isn't a unit, bcoz its so close to cubic metre..
or do you mean they require only SI units? :O

 

[Soldier313]

hmmm, for A, B and D it certainly helped
bt wat i still don't get is why area isn't a unit, bcoz its so close to cubic metre..
or do you mean they require only SI units? :O

okay look i am not sure about the SI unit thing, but area isn't a unit, a unit woud be someting yu write after a quantity, so for eg i can say 250kg, 300seconds, 500metres, but can i say 400areas? noo i can't......area is measured in metres.....not vice versa....hope you get it.....