Two blocks on a plane connected with a Rod

[Navin]

Homework Statement

Two blocks m₁ and m₂ are connected by a weightless rod are on a inclined plane of ∅=37° and μ =0.25 .What is the common acceleration and Tension of rod if m₁ is 4 kg and m₂ is 2 kg such that the 4kg block is the upper block.
OPTIONS

A =4m/² T=0
B =2m/² T=5N
C =10m/² T=10N
D = 15m/² T = 9N

Homework Equations

F=ma

The Attempt at a Solution

Looking at m₁

T + m1gsinø - friction₁ =ma
T +m1gsinø -μm1gcosø =m1a...

Looking at m₂
m2gsinø - T - μm2gcosø =m2a...[II]Adding I and II

i got a =5m/s² which is WRONG. :([/B]

 

[Merlin3189]

" Adding I and II " seems to cover a lot of maths! So I don't know what you did there.

But, how about trying the problem without the rod first? What is the acceleration of each block then?

Edit: (Gallileo might have been able to help you with this problem.)

 

[Navin]

" Adding I and II " seems to cover a lot of maths! So I don't know what you did there.

But, how about trying the problem without the rod first? What is the acceleration of each block then?

Edit: (Gallileo might have been able to help you with this problem.)

Hold on gimme a min i'll just do that

Ps - Gallileo as in the actual gallileo or a user called Ga...eo ? Cuz the actual one...is...well...asleep.And i can't seem to wake him up !

 

[Navin]

" Adding I and II " seems to cover a lot of maths! So I don't know what you did there.

But, how about trying the problem without the rod first? What is the acceleration of each block then?

Edit: (Gallileo might have been able to help you with this problem.)

Wonderful !

UR A GENIUS !
I got accelaration is 4 m/s^2 for both block ...and if i look at the option in the question A =4m/2 T=0 it makes sense as tension in the rod should be Zero because they both mobing with same accelaration hence there is no need for tension to appear.

But...why didnt i get it previosly.

Ill try it again with the rod in question

 

[Navin]

A

Wonderful !

UR A GENIUS !
I got accelaration is 4 m/s^2 for both block ...and if i look at the option in the question A =4m/2 T=0 it makes sense as tension in the rod should be Zero because they both mobing with same accelaration hence there is no need for tension to appear.

But...why didnt i get it previosly.
Ill try it again with the rod in question

OH...MY...GOD
I realized my error which i did Thrice.

Apparantly m₁ + m₂ = 2m₁

Oh my god how can i be so stoopid !

Thank you so much Merlin.
Thou Truly art as wise as the legends doth proclaim !

 

[Merlin3189]

Thanks. It's the dead one! He decided that objects fell with the same acceleration whatever their mass and supposedly dropped two cannon balls off the tower at Pisa to prove it. By extension, two blocks sliding down an incline should have the same acceleration, if all other factors like friction are the same.
So I just picked the answer with 0 tension and then tried to get the acceleration to come to 4 m/s^2. (by making g=10 m/s^2)

 

[Navin]

T

Thanks. It's the dead one! He decided that objects fell with the same acceleration whatever their mass and supposedly dropped two cannon balls off the tower at Pisa to prove it. By extension, two blocks sliding down an incline should have the same acceleration, if all other factors like friction are the same.
So I just picked the answer with 0 tension and then tried to get the acceleration to come to 4 m/s^2. (by making g=10 m/s^2)

The bodies of The Wise have long turned to dust
But their wisdom rise from their ashes
Like a phoenix.