- #1

- 99

- 4

## Homework Statement

Two blocks are connected by a thin inextensible string over a frictionless massless pulley

as shown on the picture below

The acceleration of gravity is 9.8 m/s

^{2}

Given that the two blocks move at 1.9 m/s

under an acceleration of 4.1 m/s

^{2},

calculate the coeﬃcient µk of kinetic friction between

the left block and the incline.

## Homework Equations

*ƩF=MA

F

_{f}=μ

_{k}*F

_{n}

m

_{2}-T = m

_{2}*a

*(any and all derived equations as well)

## The Attempt at a Solution

Tension minus parallel force of gravity minus force of friction equals zero because its travelling at a constant velocity.

(110kg*(9.8m/s

^{2}-4.9m/s

^{2})) - (37kg*9.8m/s

^{2}*sin(33)) - (μ*9.8m/s

^{2}*37kg*cos(33))

after doing the arithmetic and algebra i got to:

429.5138859N = (μ*9.8m/s

^{2}*37kg*cos(33))

Dividing both sides by (9.8m/s

^{2}*37kg*cos(33))

i got μ=1.412400969

I got this incorrect twice before and know have noticed my previous errors and fixed them, but was wondering if anyone can verify with me that this is the right/ wrong answer? thanks!