Physics: Post your doubts here!

[Muskan Achhpilia]

Hey,
Can anyone help me with the following MCQ.
It is from Summer 2005-:

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s05_qp_1.pdf



The answer for the question is D

Thanks a bunch!!

 

[asadalam]

anybody got an idea how to prepare for physics paper 3

 

[asadalam]

Could someone please explain these to me.God Physics mcqs are damn hard!The first ones ans is b,forgot to edit.

 

[asadalam]

Part 2

 

[asadalam]

Awesome12
Dark Destination
F.Z.M. 7
exploded diper

^^^^^ PLEASE HELP .DAMN PHYSICS

 

[Snowysangel]

yeah ofc

Isn't 0 the maximum? And it's formula is -GMm/r which implies that it should be negative right? Also. How are gravatational potential and potential energy related?

 

[Dark Destination]

Awesome12
Dark Destination
F.Z.M. 7
exploded diper

^^^^^ PLEASE HELP .DAMN PHYSICS

Which one is the toughest one?

And also, they are easy. Just relax. And think about them. You will eventually understand the MCQ.

 

[exploded diper]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_13.pdf

Q 10 pls.

force due to box= 1200 N
force due to man= 800N
resultant force = 400N
total mass of man and box = 200kg
apply F=MA
A=2 m/s2
v^2 = u^2 + 2AS
where distance (s) = 9m
so v=6 m/s

 

[asadalam]

Which one is the toughest one?

And also, they are easy. Just relax. And think about them. You will eventually understand the MCQ.

I solved most of them through common sense and tukkas,but i dont get the working in all of these.

 

[Dark Destination]

I solved most of them through common sense and tukkas,but i dont get the working in all of these.

First one requires moments. It's a couple. F * 1.20 = 900 * 0.20 ?

 

[asadalam]

First one requires moments. It's a couple. F * 1.20 = 900 * 0.20 ?

First one requires moments. It's a couple. F * 1.20 = 900 * 0.20 ?

So they are both couples?And i cant really understnad whe were multiplying 900 with 0.2,even though i know thats how we have to do it.Care to elaboratE?

 

[Dark Destination]

So they are both couples?And i cant really understnad whe were multiplying 900 with 0.2,even though i know thats how we have to do it.Care to elaboratE?

See exploded dipers diagram. 0.20 is the perpendicular distance.

 

[exploded diper]

See exploded dipers diagram. 0.20 is the perpendicular distance.

explain 29
and in 21 will we take area under the graph..

 

[Dark Destination]

explain 29
and in 21 will we take area under the graph..

29. It's because the charged particle is not being moved towards the center, work is not being done against any force.

 

[asadalam]

explain 29
and in 21 will we take area under the graph..

How does area under the graph give the answer?

 

[Dark Destination]

How does area under the graph give the answer?

Haven't you read the book? I read it just yesterday, and this was there. Area under graph is work done.

 

[exploded diper]

Haven't you read the book? I read it just yesterday, and this was there. Area under graph is work done.

but wouldnt we multiply it by 10 after tht... cuz we need the force not the mass....cuz i am getting 0.29 tht way

 

[exploded diper]

29. It's because the charged particle is not being moved towards the center, work is not being done against any force.

explain a bit more.....

 

[asadalam]

Haven't you read the book? I read it just yesterday, and this was there. Area under graph is work done.

TBH,no

 

[Dark Destination]

explain a bit more.....

In this universe, work is done against a force.

When you raise a stone through height H, you are applying force MG on it.. and work is being done against the force of gravity. Now that work appears in the form of STORED gravitational potential energy!

Same way, work is done in a spring. You do work in compressing the spring, you do work against the stiffness of the spring, and it is stored in the form of elastic potential energy.

There is Electric potential energy too. When a charge moves against a field. If you push a proton towards a positive plate, you are doing work against electrostatic repulsion so it will be stored as Electric potential energy. Work done to push it = Electric potential energy stored in it.

Now figure out the question..