Will an Applied Force of 5 N Move a 1 kg Box?

[OThePestO]

Hello people, I just joined up and I have just started to learn Physics by myself. I had originally taken Physics in high school but even though I did not get good marks I really enjoyed the concepts. I am now 28 and have completed a Honours BA in Geography and a Masters in Education. I want to learn Physics for my own personal knowledge and perhaps if possible to teach at the high school level (I think I did bad because I had a poor teacher, but I don't want to make excuses). Well I started looking at resources online and have found a site that provides a good introduction; however, I have stumbled upon a question that is giving me some trouble, here it is:

Homework Statement

http://library.thinkquest.org/10796/

You pushed a 1 kg box on floor where u= 0.3. If the force you applied was 5 N, will the box move?

Homework Equations

http://library.thinkquest.org/10796/formula.htm

Ff=uFn Fn=-mg

The Attempt at a Solution

Well I am not sure exactly what the question is asking, I was able to calculate Fn=9.8 and Ff=2.94, but how does that answer the question? In the previous chapters, I worked with mass, acceleration, time, displacement equations, and understand that I may need to combine one or more equations. Do I need to find displacement>0 in order to answer yes/no or am I looking at it wrong?

Thanks.

 

[Sakha]

In order for the box to move, your applied force (5N) has to be higher than the box's static friction. How would you express this in mathematical terms?

 

[OThePestO]

Do you mean F>Ff? If so then 5N>2.94N is true and the box moves. Is that correct?

 

[Sakha]

Yes, that's correct.

 

[rwisz]

I can provide some guidance on how to approach this question. First, it is important to understand the concept of force and how it relates to motion. Newton's Second Law states that the net force acting on an object is equal to its mass multiplied by its acceleration (F=ma). In this case, the applied force is 5 N and the mass of the box is 1 kg. This means that the acceleration of the box would be 5 m/s^2 (a=5N/1kg).

Next, we need to consider the force of friction (Ff) acting on the box. As you correctly calculated, Ff=uFn, where u is the coefficient of friction and Fn is the normal force (equal to the weight of the box, mg). In this case, the normal force would be 9.8 N (1kg x 9.8 m/s^2).

Using the formula for friction, we can calculate Ff=0.3 x 9.8 N = 2.94 N. This means that the force of friction acting on the box is 2.94 N.

Now, to determine if the box will move, we need to compare the applied force (5 N) to the force of friction (2.94 N). If the applied force is greater than the force of friction, then the box will move. In this case, the applied force is indeed greater than the force of friction, so the box will move.

In summary, by understanding the concepts of force, friction, and Newton's Second Law, we can determine that an applied force of 5 N will indeed move a 1 kg box with a coefficient of friction of 0.3. Keep up the good work in learning physics and don't be afraid to ask for help or clarification when needed. Best of luck in your studies!