Biology; Chemistry; Physics: Post your doubts here!

[KyleoAhsan]

The change in velocity is calculated by the difference in final velocity and the initial velocity!

so for your example question it had be -100 km/h
i.e. Final - Initial = 400 - 500 = -100 km/h

Velocity can be affected by two things!
That is DIRECTION and THE SCALAR QUANTITY!

In your question both is changed!

Hope it helped!

 

[Haris Bin Zahid]

The change in velocity is calculated by the difference in final velocity and the initial velocity!

so for your example question it had be -100 km/h
i.e. Final - Initial = 400 - 500 = -100 km/h

Velocity can be affected by two things!
That is DIRECTION and THE SCALAR QUANTITY!

In your question both is changed!

Hope it helped!

Thnx for helping. But kindly see (Q1-b-i) in this paper: http://www.xtremepapers.com/papers/...nal O Level/Physics (5054)/5054_w10_qp_22.pdf
The answer is (-)47 m/s. So in this way, shouldn't the answer of my above question be (-)900 km/h?

 

[KyleoAhsan]

Thnx for helping. But kindly see (Q1-b-i) in this paper: http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_w10_qp_22.pdf
The answer is (-)47 m/s. So in this way, shouldn't the answer of my above question be (-)900 km/h?

Good notice!
Sorry I misread the question!
Well if the plane is moving exactly in the opposite direction then!

The vector quantity will be negative! and hence that means
- 400 - 500 = -900 Km/h

In that paper it says exactly the opposite direction so it automatically changes to ( - )
Here is a diagram I made to show it :-
So when we find the change Final - Initial it is like this -22 - 25 = - 47 m/s


http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_w10_qp_22.pdf

 

[Haris Bin Zahid]

Good notice!
Sorry I misread the question!
Well if the plane is moving exactly in the opposite direction then!

The vector quantity will be negative! and hence that means
- 400 - 500 = -900 Km/h

In that paper it says exactly the opposite direction so it automatically changes to ( - )
Here is a diagram I made to show it :-
So when we find the change Final - Initial it is like this -22 - 25 = - 47 m/s

View attachment 13730
http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_w10_qp_22.pdf

Thnx for your consideration.

 

[scouserlfc]

So i guess now i dont have to do anything thanks to the guy above he did it the best possible way the explanation

 

[ali jahanzeb]

So whats the problem in these topics like single them out

thanks 4 response my problem in polymerisation is the method of polymerisation and in the electoplating the method of electroplating is disturbing me if any help i will be thnkful

 

[scouserlfc]

Polymerisation takes place in two methods one is the addition polymerisation and the other the condensation polymerisation .

in the first one the double bond in a alkene is broken as a result now it has a capacity accomadate two more electrons to complete valency and so it does this by attaching the same unit as itself to its sides and as a result in this same way a very big chain of polymer forms by the same monomer units which have joined together here it is always a necessity that a double bond is present in the alkenes chain which is to be broken to form the polymer ! ,at O Levels level here you dont need to know the processes of any of these polymerisation that it conditiions,what reagents are used etc all u need to know is the basic outline !

in the other one that is condensation polymerisation what happens is that two or more monomers which may be same or different join together in a complex reaction to give away water molecules and the polymer unit eg. of these are Nylon,terylene or natural polymers !

Coming to electrolysis its pretty straightforward. When electroplating there are a few things or u may call it a few rules for it !
1.the substance to be plated to is made the cathode (remember this will only be done when the metal is being used to plate the substances surface )
2.Metal which is used to plate is made the anode
3.the electrolyte used should be a compound of the metal which is being plated like if u are gold plating then u have to use the gold electrolyte !
Now the process is identical to what happens to copper in its refining the anode goes thinner and thinner while here on the cathode the substance is plated upon by the metal and the electrolytes colour if it has any remains the same as the metal ion concentration remains same as the ions replaced from electrolyte are returned by the anode back into the solution as it dissolves !

Thats abt it i guess any point i didnt cover do ask

 

[ali jahanzeb]

Thnx 4 ur help

 

[scouserlfc]

No problem !

 

[Muhammad Bin Anis]

Salam
Well i just came here if i could solve any of the people in need,, with RIGHTEOUSNESS

So tag me in for ur problems ... ( i completed my o levels in 2011)

 

[Haris Bin Zahid]

Need help in Q2.
Shouldn't the answer be A? Bcz distance from the pivot is greatest in A.

 

[abd1336480007]

how is mercury and aneroid barometer used ?

 

[Haris Bin Zahid]

scouserlfc: Man I think everyone is out on vacations and you can only help me in solving this Chemistry MCQ:
Q. Silver ions react with chloride ions.
Ag+ + Cl- -----> AgCl
It was found that 10 cm3 of a 0.05 mol/dm3 solution of the chloride of a metal, X, needed 10 cm3 of a 0.1 mol/dm3 silver nitrate solution for complete reaction. What is the formula of the chloride?
A. X2Cl
B. XCl
C. XCl2
D. XCl3

 

[scouserlfc]

scouserlfc: Man I think everyone is out on vacations and you can only help me in solving this Chemistry MCQ:
Q. Silver ions react with chloride ions.
Ag+ + Cl- -----> AgCl
It was found that 10 cm3 of a 0.05 mol/dm3 solution of the chloride of a metal, X, needed 10 cm3 of a 0.1 mol/dm3 silver nitrate solution for complete reaction. What is the formula of the chloride?
A. X2Cl
B. XCl
C. XCl2
D. XCl3

Isnt it A

 

[Haris Bin Zahid]

Isnt it A

No it isn't.
How can that be? That's the only option u can ignore straight away. Chlorine has a valency of -1 and so it can never be X2Cl.
What about the remaining three options?

 

[scouserlfc]

No it isn't.
How can that be? That's the only option u can ignore straight away. Chlorine has a valency of -1 and so it can never be X2Cl.
What about the remaining three options?

WOOPS man thanks now ill solve it correctly seriously i was playing a game and answering the question


HEHEHEH finally ill use my calculator again

 

[scouserlfc]

Its C now this should be right

 

[Haris Bin Zahid]

Its C now this should be right

Yeah. But how?

 

[scouserlfc]

Yeah. But how?

simple this is a very unique question that may come in your ATPs MCQ its based upon the fact of proportionality now us see that both chloride of X and AgNO3 have the same volume so u make that a constant and use the molarity equation which is moles/volume making volume constant u have Molarity * k (k is the volume constant)= moles so now u see that as the molarity of cl is 0.05 and its twice less than AgNO3 0.1 so the moles of cl in X will be more for the reaction like they require to be double that so as moles will double so now u can say that its formula is XCl2 u can use many ways they can be long or short its just up to you emperical formula may also come in handy

 

[Haris Bin Zahid]

simple this is a very unique question that may come in your ATPs MCQ its based upon the fact of proportionality now us see that both chloride of X and AgNO3 have the same volume so u make that a constant and use the molarity equation which is moles/volume making volume constant u have Molarity * k (k is the volume constant)= moles so now u see that as the molarity of cl is 0.05 and its twice less than AgNO3 0.1 so the moles of cl in X will be more for the reaction like they require to be double that so as moles will double so now u can say that its formula is XCl2 u can use many ways they can be long or short its just up to you emperical formula may also come in handy

Ok thnx. I got a clue now of how to solve it. But where to apply the empirical formula method?