- #1

flanders

- 10

- 0

## Homework Statement

Hi. My task is to find the Force F, so that velocity is constant.

I know that the velocity is constant, therefore the sum of all forces must be zero!

On the image I have used vector decomposition (the black lines). The orange ones are the vectors.

I know that the angle is 36,9 degrees. (the one marked with a half a circle).

I also know that the friction number is 0,25.

Explanation of the attached image:

G = Gravity

N = Normal Force

Ff = Friction

F = The force I must find

## Homework Equations

[tex]Gx=0,6mg[/tex]

[tex]Gy=0,8mg[/tex]

[tex]Fx=0,8ma[/tex]

[tex]Fy=0,6ma[/tex]

[tex]\mu \; =\; 0.25[/tex]

[tex]N = Gy + Fy[/tex]

## The Attempt at a Solution

I have tried to find N by using this formula:

[tex]\mu \; =\; \frac{Ff}{N}[/tex]

Then I thought that I could find Fy and Fx and use Phytagoras to find F. But my idea doesn't work (at least not the way I did it).

I don't know how to think to solve this one... The mass is unknown and frustrates me alot. Can anyone give me a tip?

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