# Force questions

1. Feb 5, 2008

### ultimasayan

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can someone help me please with these questions?
i have read all the newton law but still not understanding these question properly

1.what is an force?
2.how do we know a force is acting?
3.what effect can force have?

2. Feb 5, 2008

### qspeechc

1) A force is that entity that tends to cause a body of mass to accelerate.
2) This is tricky. I think they mean "how do we know when a net force is acting", and the answer would be:"we observe an acceleration of the body to which the force is applied"
3) Acceleration; deforming a body.

3. Feb 5, 2008

### Sdawg1969

in definition F=ma from newtons law- m in kg and a in m/s so you end up with a kg*m/s, which is called a newton. An example...

You have a 300g ball on a string, what is the force of gravity on the ball?

F=ma

acceleration due to gravity is 9.8m/s$$^{}2$$ so...

F=?

4. Feb 5, 2008

### kbaumen

a is m/s$$^{2}$$ so you actually end up with $$\frac{kg * m}{s^{2}}$$ which really is called a newton, denoted as N.

5. Feb 5, 2008

### Littlepig

Well, can change mass and can change velocity...i guess that's it...

6. Feb 5, 2008

### rock.freak667

A force is what causes a mass to accelerate.

A force acts when a body is "accelerating" so to say
A force can cause a mass to accelerate,change velocity(and speed)

7. Feb 6, 2008