What Forces Affect Motion in Block Dynamics?

[berkeman]

Well, the 231.3 value of M2 should be enough to break the M1 block free and start it sliding. I'd thought for a moment that the answer might be a=0 for the 3rd question, if M2 were not heavy enough to start the pair sliding.

I'm not sure what we could be missing. I've asked for other Homework Helpers to take a look at this thread, to see if they see something that should be corrected. I'll keep looking at it, and hopefully you will get somebody else to check out the work. Post a reply to my post here, so that your name shows up at the end of the thread instead of mine (that will help you get others to look in).

 

[berkeman]

I just got word from one of the HH'ers, and we have been forgetting the vertical component of M1's weight in the force summation equation. As the ramp angle gets steeper, the normal force gets less, and the vertical component of the weight of M1 gets bigger.

Can you account for that vertical component of M1's weight in the force summation?

 

[Doc Al]

What you're missing is component of M1's weight parallel to the incline when finding ƩF.

 

[berkeman]

What you're missing is component of M1's weight parallel to the incline when finding ƩF.

Thanks Doc!

 

[superhero241]

so.. what to do?

 

[gneill]

When in doubt, re-evaluate your current situation.

List the forces operating to cause or impede motion on each block. Specify numerical values if you have them, otherwise just indicate the variable name.