ALL CIE PHYSICS DOUBTS HERE !!!

[S.M.A.T]

nice work thought i posted the same working check my post , lol the answer was simple it was just that i didn't concentrate .... EXAMMMMMMMMMMMMMMMMMMs ss

SORRY i didn't notice. ...+rep for your work

[lana]

could someone please explain to me to estimating uncertainties ??
thanks =]

[Ivo]

yes this is what i meant to say 

So when an object is in equilibrium,the frictional force will take a value equal to the horizontal force

Just to make sure, so can I say for part iii) That because the system is in equlibrium, there is no resultant force acting on the skier.  Therefore, the friction force exerted by the bed is said to be equal to the net horizontal forces exerted by the tension of the rope?

What I'm not sure about is should I say 'net', and should I say 'taking into account of horizontal components'. 

Also, I'm not sure about the directions of Tension that should be on the question.  Here's my attempt, please could someone correct me.  I'm not sure if there should be a Tension force on the horizontal right at the top of the system.

[Deadly_king]

could someone please explain to me to estimating uncertainties ??
thanks =]

Try this :

 http://www.astarmathsandphysics.com/a_level_physics_notes/principles_dimensions_units_error_analysis_etc/a_level_physics_notes_error%20analysis%281%29.html

If ever you need some explanation from us, post a question!

It's easier to explain when answering to an appropriate question

[Deadly_king]

Just to make sure, so can I say for part iii) That because the system is in equlibrium, there is no resultant force acting on the skier.  Therefore, the friction force exerted by the bed is said to be equal to the net horizontal forces exerted by the tension of the rope?

What I'm not sure about is should I say 'net', and should I say 'taking into account of horizontal components'. 

Also, I'm not sure about the directions of Tension that should be on the question.  Here's my attempt, please could someone correct me.  I'm not sure if there should be a Tension force on the horizontal right at the top of the system.

Yeah..........the word net fits exactly here. Your answer is right

For the tensions, I think all of them should be directed towards the pulleys. Hence the horizontals will have tensions in both directions.

But am not 100% confident about that

[lana]

Thank you sooo much =]

Try this :

 http://www.astarmathsandphysics.com/a_level_physics_notes/principles_dimensions_units_error_analysis_etc/a_level_physics_notes_error%20analysis%281%29.html

If ever you need some explanation from us, post a question!

It's easier to explain when answering to an appropriate question

[Deadly_king]

Thank you sooo much =]

You're welcome dear

[Ivo]

Hmm, don't really know how to start this!

[Ivo]

Hmm, don't really know how to start this!

Here are my answers - I doubt my abilities though!

a) 5600N

b) 1600N

c) 1600N

[ashish]

Here are my answers - I doubt my abilities though!

a) 5600N

b) 1600N

c) 1600N

for part a
F=ma
 =(3000+4000)*0.8
 =5600N

B)
total force is 5600 N
net force acting on 1^st trailer will be 5600- ( 3000*0.8 )
                                                                =3200N

c)5600-((3000+2000)*0.8 )
=1600N

[TJ-56]

someone please explain

http://img201.imageshack.us/img201/5643/unfi.jpg

[$!$RatJumper$!$]

someone please explain

http://img201.imageshack.us/img201/5643/unfi.jpg

This should answer your question. If it isn't clear let me know

http://i53.tinypic.com/jawhgp.jpg

[TJ-56]

Thanx for the answer and sorry for the late reply, +rep

[TJ-56]

june 05 q13 paper 1
thanx in advance

[Deadly_king]

june 05 q13 paper 1
thanx in advance

Moment is defined as the product of the force to the perpendicular distance from the pivot.

Total clockwise moments = 20(3)

Total anti-clockwise moment = 5(2) + 10(2)

Resultant moment = 20(3) - [5(2) + 10(2)] = 30Nm

NOTE : For the 10N force, the perpendicular distance from P is 2m since the line of action of the force is horizontal.

Hope it helps