- #1
SinghTjay
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Homework Statement
Two blocks are joined together with a rope that runs over the pulley. The mass of m2 is 5kg and the incline is 35 degrees (m2 hangs off the edge of the ramp, pulling on m1). The coefficient of static friction between mass 1 and the inclined board is 0.2. Determine the largest mass for m1, so that both blocks remain stationary. (m1 does not slide down).
Homework Equations
f=ma
Force friction=coefficient(Force normal)
The Attempt at a Solution
Force friction = 0.2(Fn)
=0.2(m)(g)(cos35)
Force Friction = 1.61m
Because block 2 pulls with 49N of force [5(9.8)], then I assume the force of friction on block 1 is 49N. However, gravity pulls down on the block 1 as well (Fgx=m9.8sin35=5.62m). So:
Ff=1.61m
49N-5.62m=1.61m
Gravity reduces the amount of friction required to hold block 1 in place.
Therefore:
m=49/7.23
m=6.8kg
The listed answer is 14kg.
What am I doing wrong?
Thank You