- #1
gerard.caleb
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Homework Statement
2. A block of mass 35 kg is on a flat floor with a static friction coefficient of 0.36 and a kinetic friction coefficient of 0.29. A person attempts to slide the box from rest in a forward direction. Find the maximum frictional force experienced and the acceleration of the box once it is moving if:
a) the person pushes horizontally with 120 N.
m=35kg
μs=0.36
μk=0.29
Homework Equations
Fnet=m*a
Fnorm=g*m
μk=Fnet/Fnorm
The Attempt at a Solution
*Disclaimer: I'm taking an online class with very few sample questions so I will not be held liable for any injuries that occur due to facepalming at my attempts to solve these*
Fn=m*g
Fn=35kg*9.8kg/N
Fn= 343N
F=Fn*μs
F=343N*0.36
F=123.48N
So 123.48N is the maximum friction force experienced?
And the acceleration can be found from:
We know uK=0.29
And uK=Fnet/Fnorm
So 0.29=Fnet/343N
0.29*343N=Fnet
99.47N=Fnet
We know Fnet=m*a, so:
99.47N=35kg*a
a=2.842m/s^2
So acceleration is 2.842m/s^2?
I am 20000% percent sure that I have these wrong because I didn't include the applied force given in the question at all (among other reasons).
I have a few other questions similar to this but involving angles and different applied forces, I'm sure once I understand how to do this one I can do the others, but I thought the most basic one would be a good starting place for someone here to point out my errors.
Thank you!