# Force questions

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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?

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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.

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=?

ia in m/s so you end up with a kg*m/s, which is called a newton.
F=?
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.

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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?
Above all, it's a Human Concept;
them, it's a concept that was made to explain a phenomena;

than yes, Is the variation of velocity and or mass with time, that is dp/dt.
you can see force as variation of energy(not energy but momentum) that a body as.

2.how do we know a force is acting?

By the definition, dp/dt, measuring mass and velocity, if 1 of witch is changing with time, them a force is acting on that object.(classical mechanics...)

3.what effect can force have?
Well, can change mass and can change velocity...i guess that's it...

rock.freak667
Homework Helper
1.what is an force?
A force is what causes a mass to accelerate.

2.how do we know a force is acting?
A force acts when a body is "accelerating" so to say
3.what effect can force have?
A force can cause a mass to accelerate,change velocity(and speed)