What is the required force to push a box upwards on an angled surface?

  • Thread starter Waelroe
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    Friction
In summary, the conversation discusses a box being placed on an angled surface and whether it will slip downwards if a certain force is applied. The force needed to push the box upwards is also considered. The solution is found by calculating the downward and upward forces, with the correct value for the downward force being mgcos(35).
  • #1
Waelroe
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Homework Statement


A box is placed on an angeled surface.

m = 15 kg
f = 0,3

[PLAIN]http://img5.imageshack.us/img5/8717/friction.png

Will the box slip downwards if X = 0?

How big does the force X have to be to push th box upwards?

Homework Equations


The Attempt at a Solution


My idea was that the only force working upwards is Ff.

A = 55°
g = 9,81
N = mg*cos(90-35)+18 = 102,40 N

Ff = 0,3*N = 30,72

Force downwards: mgcos35-18 = 102,54 N

The force down is greater than Ff therefore it would slip if X = 0.To get how big X needs to be to make the box move up i simply subtracted the force down with Ff and got = 71,82 N.Could this possibly be correct?
 
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  • #2
Why is your downward force mgcos(35)-18? It should just be mgcos(35)
 
  • #3
Pi-Bond said:
Why is your downward force mgcos(35)-18? It should just be mgcos(35)


Yea, okey. So the rest would be correct then?
 
  • #4
After changing the value of the downward force, yes.
 
  • #5


Your calculations are correct. To push the box upwards on the angled surface, a force of at least 71.82 N is required. This is because the force of friction (30.72 N) is not enough to counteract the downward force of gravity (102.54 N). Therefore, an additional force (X) is needed to overcome the difference between the two forces and push the box upwards. If X is less than 71.82 N, the box will not move upwards and will slip downwards.
 

FAQ: What is the required force to push a box upwards on an angled surface?

1. What is a friction angled surface?

A friction angled surface is a surface that has a slope or incline, causing objects to slide or move down the surface due to the force of gravity and the resistance of friction.

2. How does friction affect objects on a friction angled surface?

Friction acts against the motion of objects on a friction angled surface, making it more difficult for them to move or slide down the surface. The steeper the angle of the surface, the greater the frictional force acting on the object.

3. What factors affect the amount of friction on a friction angled surface?

The amount of friction on a friction angled surface is affected by the weight of the object, the type of surface material, and the angle of the surface. The rougher the surface and the steeper the angle, the more friction will be generated.

4. How can friction on a friction angled surface be reduced?

Friction on a friction angled surface can be reduced by using a lubricant, such as oil or grease, to create a layer between the object and the surface. Additionally, using a smoother surface material or decreasing the angle of the surface can also reduce friction.

5. What are some real-life examples of friction angled surfaces?

Some real-life examples of friction angled surfaces include ramps, slides, and inclined planes. These surfaces are commonly used in playgrounds, construction sites, and for loading and unloading heavy objects.

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