- #1

SakuRERE

- 68

- 5

## Homework Statement

In the figure above a block of mass m is connected to a block of mass M > m by a string. Both blocks sit on a smooth surface with a coefficient of kinetic friction µk between either block and the surface. In figure a), a force of magnitude F (large enough to cause both blocks to slide) is exerted on block M to pull the system to the right. In figure b), a force of (the same) magnitude F is exerted on block m to pull the system to the left. Circle the true statement:

a) The tension Ta > Tb.

b) The tension Ta < Tb.

c) The tension Ta = Tb.

d) There is not enough information to determine the relative tension in the two cases.

known data:

we know that both blocks have the same coefficient of friction and that their masses are different.

## Homework Equations

ΣF= ma

μk= Fk*N

## The Attempt at a Solution

I drew first the FBD of both block in each situation and wrote the equation. for the first situation (a)

Block M has this equation:

ΣF= ma

F-Ta-Fk=Ma

Ta=F-Fk-Ma

*Ta=F-μkMg-Ma*

while block m I ended up with:

Ta=ma+μkmg

and for the second situation:

block M equation:

Tb= Ma+μkMg

and block m:

Tb=F-μkmg-ma

so I said since larger mass has larger KInetic Friction Fk, compared to the small one, and because of comparing the Ta equation of M and the Tb equation of M then Tb I guess is bigger.

I don't know if I
am right or not.

while block m I ended up with:

Ta=ma+μkmg

and for the second situation:

block M equation:

Tb= Ma+μkMg

and block m:

Tb=F-μkmg-ma

so I said since larger mass has larger KInetic Friction Fk, compared to the small one, and because of comparing the Ta equation of M and the Tb equation of M then Tb I guess is bigger.

I don't know if I