- #1

abpandanguyen

- 33

- 0

## Homework Statement

A block of mass m

_{1}= 2.0 kg is stacked on top of a block of mass m

_{2}= 3.0 kg which is resting on top of a table

Both blocks and the table are made of the same material; so the coefficients of friction between all surfaces are the same

They are (attempt at a mew)

*m*

_{s}= .60 and

*m*

_{k}= .40.

A constant force

*F*is applied horizontally to m

_{2}. When

*F*is small, the two blocks move together with the same acceleration. At some point as

*F*is increased, the top block will no longer move with m

_{2}.

a. What is the minimum force F

_{min}that is needed to start the two blocks moving?

b. What is the maximum force F

_{max}that allows the two blocks to move together?

## Homework Equations

F=ma

F

_{s}=

*m*

_{s}n

F

_{k}=

*m*

_{k}n

## The Attempt at a Solution

For a, I just added the two masses together and multiplied by g to get a total N then multiplied that by the coefficient of static friction to get the force required to get the two blocks moving. I hope that is right.

For b, I am having a difficult time imagining what m

_{1}(mass on top) is doing when the horizontal force applied to m

_{2}(mass on bottom) gets larger. I'm assuming this problem requires the use of F=ma. I'm having trouble picturing all the forces in motion here as the horizontal force on m

_{2}increases, particularly what is happening to the mass on top.

Any help would be much appreciated! Please and thank you!

Sorry I didn't make a picture for this. I'm on a computer where paint isn't even an option. >__<;;