Calculating Force and Acceleration in a Two Block System with Varying Friction

[BEORTA39]

Homework Statement

in the A we need to find the force and acceleration of the system when we pull the lower block and the upper mass starts to move

in B we need to find the force and acceleration of the system when we pull the upper block and the upper mass starts to move

the friction before the lower mass and the floor is µ and the friction between the upper and lower mass is 3µ

please help me with that

Relevant Equations

newton laws

in the A we need to find the force and acceleration of the system when we pull the lower block and the upper mass starts to move

in B we need to find the force and acceleration of the system when we pull the upper block and the upper mass starts to move

the friction before the lower mass and the floor is µ and the friction between the upper and lower mass is 3µ

please help me with that

 

[PeroK]

The homework guidelines require that you make a serious attempt at the problem yourself. Do you understand the problem logically? Can you explain what will happen, before you do any calculations?

https://www.physicsforums.com/threads/homework-help-guidelines-for-students-and-helpers.686781/

 

[BEORTA39]

Of course, I don't need anyone to solve my problem only to guide me where to start.

about the problem yes I do understand that i have one block in acceleration (lower one) and the other that starts to slide is affected by friction(static) force and i need to find F and a of the system what i tried to do is drawing forces like all forces problems and then creating equations to solve the problem the place where i stack is understand is i draw the forces correct. because upon that i create my equations

 

[PeroK]

about the problem yes I do understand that i have one block in acceleration (lower one) and the other that starts to slide is affected by friction(static) force and i need to find F and a of the system what i tried to do is drawing forces like all forces problems and then creating equations to solve the problem the place where i stack is understand is i draw the forces correct. because upon that i create my equations

First, it's hard to read something with no punctuation. Second, I don't think you have understood the problem.

 

[Lnewqban]

Welcome!

Separate the blocks from each other and the floor.
Then, draw a free body diagram for each block, including only force vectors acting on each, including weight and friction.

 

[BEORTA39]

Please guys i think i fix it just tell me if my corrections is better now only. so i can sleep well

 

[phinds]

Very few here can read Hebrew. Forum rules say everything must be posted in English