Immediately after a summer thunderstorm, you decide to move your rubber deck box. The cement is wet so the coefficient of friction between the rubber deck box and the cement is 0.40. How much force do you need to push the 150 N deck box across the cement at a constant speed of 1.6 m/s.

Question

Immediately after a summer thunderstorm, you decide to move your rubber deck box.  The cement is wet so the coefficient of friction between the rubber deck box and the cement is 0.40.  How much force do you need to push the 150 N deck box across the cement at a constant speed of 1.6 m/s.

anonymous · Answer

What is the formula for a problem like this?

fifciol · Answer

$$F_{fr}=\mu_kW$$
Now tell me what condition must be met to move this object at constant speed? In other words how strong must be the force that you apply to move this object at constant speed(newton's first law)

fifciol · Answer

W is the weight of an object

fifciol · Answer

|dw:1388858199367:dw|
how strong must be your force to move that object at constant speed?(doesn't need to be 1.6 m/s)

anonymous · Answer

yes.  I believe so.

anonymous · Answer

This is the first time I have done a problem like this I am just trying to practice for a test.

anonymous · Answer

WHat is the formulas name?  What kind of formula is it?

fifciol · Answer

newton's first law

fifciol · Answer

if the object is not moving or moving with constant velocity the sum of all forces acting upon it must be equal to zero

fifciol · Answer

so what must be your force equal to ?

fifciol · Answer

your force must be simply equal to that frictional force. Can you now write down equation?

anonymous · Answer

what does the fr part mean?

fifciol · Answer

frictional

anonymous · Answer

force*frictional =that symbol k W

anonymous · Answer

I don't have a book for this class so I don't really have any of the formulas or anything.  I am just trying to look it all up onine

fifciol · Answer

$$\mu_k$$is the friction coefficient = 0.40

anonymous · Answer

okay now I can figure it out.

anonymous · Answer

Where would I put the 1.6 in the equation?

anonymous · Answer

WOuld it be F

fifciol · Answer

nowhere, you don't need that. The information that you need is constant speed, that's what matters. Newtons law doesn't care about how big is that speed(unless it's a speed approaching speed of light)

anonymous · Answer

oh okay.

anonymous · Answer

60 N

anonymous · Answer

????

anonymous · Answer

I think I did it right.

fifciol · Answer

yes, that's correct

anonymous · Answer

Yes!!!!