Kinematics Help

[bsmith6661]

The problem statement and diagram is attached.

 

Write a MATLAB code for the mechanism that uses phi at the independent variable and solve for the following parameters when phi=30°, 150°, 260°, and 310°.

a. Angular velocity of link 3
b. Angular acceleration of link 3
c. Linear velocity of point E
d. Linear acceleration of point E
e. Motor torque with external force, Fe

I don't necessarily need the MATLAB code, as I can figure that out. My trouble lies within figuring out the Kinematic Equations. Would I need to figure out a system of equations (ex. 5 equations, 5 unknowns) or could they all be solved for independently? I'm pretty sure that the 'syms' function in MATLAB accounts for this.

This exact same problem is on Chegg, but I believe it is wrong. I have attached it below. My main questions have to be: Why wasn't phi or the mass of the sliders/links accounted for (and how would you do that, if they need to be)? And why are they dividing by 0.02 in step 1?
 
I will be reviewing this material during the coming weeks, and I would just like to understand what is going on with this system, especially since my book doesn't have any similar examples in it. Any and all explanations are appreciated!

[studiot]

1 hour ago, bsmith6661 said:

I don't necessarily need the MATLAB code, as I can figure that out. My trouble lies within figuring out the Kinematic Equations. Would I need to figure out a system of equations (ex. 5 equations, 5 unknowns) or could they all be solved for independently? I'm pretty sure that the 'syms' function in MATLAB accounts for this.

 

I can't help you with MAtLab, perhaps someone else here can do that.

For the mechanics part your question asks about forces as well as velocities and accelerations.
Strictly speaking kinematics refers only to the velocities, times, distances and accelerations, without consideration of the forces and energies to achieve them.
The subject including those is called dynamics.

Either way you need to establish a system of simultaneous equations to find what you need.

These come from the laws of kinematics and or dynamics and are called the constitutive relations.

By themselves there will be more unknowns that equations.

So you then have to look elsewhere to obtain more equations to solve the system.

These come from the geometrical constraints on the system (for instance the distance AB is fixed, although B moves about) and are called the constraint equations or the equations of compatibility.

You can google both these terms, I'm sure from the complexity of your question you will need to know about them in your studies.

Does this help?