Home » Ask & Discuss » Physics. » Mechanics « Back to Discussion

Mechanics

Cool goIITian

Joined:	14 Mar 2008
Post:	36

28 Mar 2008 12:37:48 IST

0 People liked this

752

friction... a B.MAT question....proper solution required.......

None

two blocks of masses ma=2kg and mb=4kg are kept on an inclined plane of inclination = 37degree as shown.The coefficient of friction bw A and B is 1 and bw B and surface is 2. accelerations of blocks A and B are a1 and a2. then match the following. column I &nb

Share this article on:

Comments (11)

BALGANESH

Blazing goIITian

Joined: 21 Dec 2007

Posts: 1025

28 Mar 2008 13:36:00 IST

Like 1 people liked this

since they have common acceleration
they can be considered as a system
now for the system of A&B
mgsin37 -

₂ mgcos37 = ma
gsin37 -

₂ gcos37 = a
simplifying we get
6 - 8

₂ = a ---------------------(1)

now for block A
mgsin37 +

₁ mgcos37 - ma (pseudo force)= 0
gsin37 +

₁ gcos37 = a
simplifying we get
a = 6 + 8

₁ --------------------------(2)
from 1 and 2
6+8

₁ = 6 - 8

₂
or

₁ = -

₂

therefore it is option B

correct me if i"m wrong

BALGANESH

Blazing goIITian

Joined: 21 Dec 2007

Posts: 1025

28 Mar 2008 15:22:23 IST

Like 1 people liked this

i think 3 is A and C

₁ mgs = 0

₁ =0
case 2

₂ mgs = 0

₂ =0

therefore it is A and C

anchit saini

Blazing goIITian

Joined: 1 Feb 2008

Posts: 1251

28 Mar 2008 15:36:01 IST

Like 1 people liked this

what i think is that since u have said a1 = a2 only when option B is correct
hence
a1 ! = a2 when option a,c,d are correct

sharmadon

Cool goIITian

Joined: 14 Mar 2008

Posts: 36

29 Mar 2008 21:20:44 IST

Like 0 people liked this

hey the answrs according to the solution given by Brilliant tutorials is:

1. A,B

2. C,D

3. A,B,D

4. A,C

and my friend ganesha..u can consider it as a system only wen u can confirm that they move together..please justify...

i am really very tensed about such kind of questions..pls somebody help........with proper solution..

vidyarthi

New kid on the Block

Joined: 31 Mar 2008

Posts: 9

31 Mar 2008 13:54:32 IST

Like 0 people liked this

http://www.locuseducation.org/component/option,com_fireboard/Itemid,26/func,view/catid,10/id,524/#524

GAURAV SHARMA

Hot goIITian

Joined: 7 Aug 2007

Posts: 184

31 Mar 2008 22:15:26 IST

Like 0 people liked this

THE FIRST PART..

GAURAV SHARMA

Hot goIITian

Joined: 7 Aug 2007

Posts: 184

31 Mar 2008 22:16:32 IST

Like 0 people liked this

SECOND AND THIRD PART..

GAURAV SHARMA

Hot goIITian

Joined: 7 Aug 2007

Posts: 184

31 Mar 2008 22:17:31 IST

Like 0 people liked this

FOURTH PART..

BALGANESH

Blazing goIITian

Joined: 21 Dec 2007

Posts: 1025

31 Mar 2008 22:18:10 IST

Like 0 people liked this

ok for the first one A is correect
as there is no friction between the wedge and block B the whole A and B can be considered as one system with common acceleration

so from my present and previous post
the answer for 1 is
A) and B)

BALGANESH

Blazing goIITian

Joined: 21 Dec 2007

Posts: 1025

31 Mar 2008 22:20:14 IST

Like 0 people liked this

since a1 is not equal to a2 the other two options must be true fior this
therefore for 2 answer is
C) , D)

[ thanks anchit]

vidyarthi

New kid on the Block

Joined: 31 Mar 2008

Posts: 9

1 Apr 2008 14:34:27 IST

Like 0 people liked this

http://www.locuseducation.org/component/option,com_fireboard/Itemid,26/func,view/catid,10/id,528/#528

Quick Reply

Reply

	Some HTML allowed.
	Keep your comments above the belt or risk having them deleted.
	Signup for a avatar to have your pictures show up by your comment
	If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team