All Mechanics DOUBTS HERE!!!

[thecandydoll]

I just realised thats the frictional force!
TTHANKK YOU
scratch that

[Ghost Of Highbury]

winter 2009, paper 41..

Q4..

(AS level)

Could someone plz include diagrams and explanations in the answer...thanks a lot..

[Deadly_king]

winter 2009, paper 41..

Q4..

(AS level)

Could someone plz include diagrams and explanations in the answer...thanks a lot..

i) First you need to resolve vertically so as to find the reaction.
R = 80 x cos 20 = 75.2 N

Since the block is at rest ----> a = 0
Using Newton's second law of motion : F = ma
T + Fr - mgsin x = ma
where T : tension in the string,
Fr : frictional from between block and the inclined plane
mgsin x : component of weight down the plane and x being the angle of inclination of the plane

Given T =13 and a=0 ----> 13 + Fr - 80sin 20 = 0
Hence Fr is found to be 14.4 N

ii) String is cut off but block is still at rest ----> Fr = mgsin x

Fr = uR where u is the coefficient of friction between block and plane

Hence 80sin 20 = u(75.2) -----> u = 0.364

Sorry I could not add a diagram

Hope it helps

[Ghost Of Highbury]

i) First you need to resolve vertically so as to find the reaction.
R = 80 x cos 20 = 75.2 N

Since the block is at rest ----> a = 0
Using Newton's second law of motion : F = ma
T + Fr - mgsin x = ma
where T : tension in the string,
Fr : frictional from between block and the inclined plane
mgsin x : component of weight down the plane and x being the angle of inclination of the plane

Given T =13 and a=0 ----> 13 + Fr - 80sin 20 = 0
Hence Fr is found to be 14.4 N

ii) String is cut off but block is still at rest ----> Fr = mgsin x

Fr = uR where u is the coefficient of friction between block and plane

Hence 80sin 20 = u(75.2) -----> u = 0.364

Sorry I could not add a diagram

Hope it helps

erm, is that question 4 of winter 2009 M1 (paper 41) paper? :-/

[The Golden Girl =D]

Hey ,I just wanted to know How Am i supposed to study for M1 , I want to know what is the best way to study for this Subject ?

Because i got this really Low grade in the Quiz and I don't want to show my Dad :S  Since I'm dead meat for sure 

Thank You In Advance .

[elemis]

@GG are you doing Edexcel or CIE M1 ?

[SpongeBob]

winter 2009, paper 41..

Q4..

(AS level)

Could someone plz include diagrams and explanations in the answer...thanks a lot..

I hope you understood the post above :/

Nov 09 Q4 --> https://studentforums.biz/math-146/mechanics-question/15/

Is this the one?

[Deadly_king]

erm, is that question 4 of winter 2009 M1 (paper 41) paper? :-/

That was June 09 p4 No4

[The Golden Girl =D]

@GG are you doing Edexcel or CIE M1 ?

Edexcel

[Deadly_king]

Hey ,I just wanted to know How Am i supposed to study for M1 , I want to know what is the best way to study for this Subject ?

Because i got this really Low grade in the Quiz and I don't want to show my Dad :S  Since I'm dead meat for sure 

Thank You In Advance .

M1 is supposed to be easy especially for those doing physics.

Hmm............studying M1 does not actually require much knowledge. You just need to understand the basic principles. Then only practice might help you perform well

[The Golden Girl =D]

M1 is supposed to be easy especially for those doing physics.

Hmm............studying M1 does not actually require much knowledge. You just need to understand the basic principles. Then only practice might help you perform well

Practice ..Ohh Ya :S :S

Thanks 

[**RoRo**]

Mechanics shall drive me nuts soon!! :/

Question, from the chapter vectors, I came across this question and I got the answer from the CD that came with the book, but I can't understand

Q. An aeroplane flies from airport A to airport B 80 km away on a bearing of 070?. From B the aeroplane flies to airport C, 60 km from B. Airport C is 90 km from A. Find the two possible directions for the course set by the aeroplane on the second stage of its journey.

Ans. ?cos?? =(6²+8²?9²) / (2×6×8) =0.19791…
? =78.6°(3 s.f.)

?bearing ofC from B is
180°+70°??=171.4°(1 d.p.) or 180°+70°+?=323.6°(1 d.p.)

& the diagram that they showed is attached below.

I don't understand how did they reach to this diagram and hence the solution!

Any help will be much appreciated!

Thanks a lot in advance!

[ashish]

Mechanics shall drive me nuts soon!! :/

Question, from the chapter vectors, I came across this question and I got the answer from the CD that came with the book, but I can't understand

Q. An aeroplane flies from airport A to airport B 80 km away on a bearing of 070?. From B the aeroplane flies to airport C, 60 km from B. Airport C is 90 km from A. Find the two possible directions for the course set by the aeroplane on the second stage of its journey.

Ans. ?cos?? =(6²+8²?9²) / (2×6×8) =0.19791…
? =78.6°(3 s.f.)

?bearing ofC from B is
180°+70°??=171.4°(1 d.p.) or 180°+70°+?=323.6°(1 d.p.)

& the diagram that they showed is attached below.

I don't understand how did they reach to this diagram and hence the solution!

Any help will be much appreciated!

Thanks a lot in advance!

it's like or it's a locus question.
locus of a point of r cm is a circle with radius r cm
 and in this particular question C will be where the two circle intersect each other

sorry for the handwriting

[**RoRo**]

it's like or it's a locus question.
locus of a point of r cm is a circle with radius r cm
 and in this particular question C will be where the two circle intersect each other

sorry for the handwriting

Ohhh, now that makes sense!

Thanks a lot! 

[**RoRo**]

One more question!

A particle P is moving along the x-axis with constant deceleration 2.5ms^?2. At time t=0s, P passes through the origin with velocity 20ms^?1 in the direction of x increasing. At time t=12s, P is at the point A. Find

(a) the distance OA,

(b) the total distance P travels in 12 s.


The answer for (a) is 60m and for (b) it's 100m.

HOW?