What is the Frictional Coefficient for this Homework Statement?

[Priyadarshini]

Homework Statement

Homework Equations

a=meu*g

The Attempt at a Solution

meu= 20/10
= 2
The answer's wrong

 

[Suraj M]

Myu*g? What is that suppose to be?
Don't just apply the formula you've learnt,
Identify the normal force

 

[Priyadarshini]

Myu*g? What is that suppose to be?
Don't just apply the formula you've learnt,
Identify the normal force

The normal force here is the driving force of the vehicle, which is it's mass times the acceleration

 

[cnh1995]

The normal force here is the driving force of the vehicle, which is it's mass times the acceleration

You've got the concept right. Check the math again.

 

[Suraj M]

Exactly so the formula for frictional force is?
Do you thing myu*g represent the frictional force now?

 

[Priyadarshini]

Exactly so the formula for frictional force is?
Do you thing myu*g represent the frictional force now?

The firctional force is meu*normal force, so the frictional force is meu*M*a
Can I do this:
The driving force- frictional force = (M1+M2) a
friction= [F-(M1+M2)a]
so meu = [F-(M1+M2)a]/M1a
meu= [M1a - (M1+M2)a]/M1a
meu = M2/M1
But then what?

 

[Chestermiller]

Actually, 3 of the answers are correct. Static friction is determined by $N\mu \geq F$ for no slippage, not $N\mu = F$

 

[cnh1995]

What is the acceleration of the smaller block?

 

[Priyadarshini]

What is the acceleration of the smaller block?

Isn't the acceleration 20m/s^2 for both the blocks?

 

[cnh1995]

Yes. That is what is needed. Write the equation for forces "on" the smaller block. You'll get the value of friction coeff just to avoid slipping. You'll see Chestermiller's reply makes true sense!

 

[Chestermiller]

Isn't the acceleration 20m/s^2 for both the blocks?

Have you drawn a free body diagram showing the forces acting on the smaller mass, or do you feel like you have advanced to the point where you no longer need to use free body diagrams?

 

[Priyadarshini]

Have you drawn a free body diagram showing the forces acting on the smaller mass, or do you feel like you have advanced to the point where you no longer need to use free body diagrams?[/QUOTE ]

 

[Priyadarshini]

Have you drawn a free body diagram showing the forces acting on the smaller mass, or do you feel like you have advanced to the point where you no longer need to use free body diagrams?

Yes. That is what is needed. Write the equation for forces "on" the smaller block. You'll get the value of friction coeff just to avoid slipping. You'll see Chestermiller's reply makes true sense!

Got it! Thank you!

 

[Chestermiller]

View attachment 95008
Got it! Thank you!

I knew the FBD would do the trick.