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Finding magnitude of force (involving mass at velocity from rest in seconds with coef

 
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Apr26-11, 12:43 PM   #1
 

Finding magnitude of force (involving mass at velocity from rest in seconds with coef


1. The problem statement, all variables and given/known data
A certain force moves a 4kg box from rest to a velocity of 6m/s in 3 seconds. If the coefficient of friction between the box and floor is 0.05, what is the magnitude of the force?

m=4kg
v0=0
v=6m/s
t=3s
μk=0.05
2. Relevant equations
a=v/t
F0=mg
P=Ft
P=mv

3. The attempt at a solution
a=(6)/(3)=2m/s
F0=(4)(9.8)=39.2N
Pc=(39.2)(3)=117.6
P=(4)(6)=24
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution
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Apr26-11, 01:30 PM   #2
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Quote by bearsa113609 View Post
1. The problem statement, all variables and given/known data
A certain force moves a 4kg box from rest to a velocity of 6m/s in 3 seconds. If the coefficient of friction between the box and floor is 0.05, what is the magnitude of the force?

m=4kg
v0=0
v=6m/s
t=3s
μk=0.05
2. Relevant equations
a=v/t
F0=mg
P=Ft
P=mv

3. The attempt at a solution
a=(6)/(3)=2m/s
F0=(4)(9.8)=39.2N
Pc=(39.2)(3)=117.6
P=(4)(6)=24
HINT:
You've found the acceleration. Can you use that to find the net force, and then, from there, the unknown applied force?


You don't need momentum or impulse for this problem.
Aug4-12, 12:01 AM   #3
 
thank you so much
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coefficient, force, friction, magnitude, physics
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