# Is there any way that newton's second law can be derived from the

1. Jul 25, 2012

### Nstraw

Is there any way that newton's second law can be derived from the first

2. Jul 25, 2012

### Nstraw

Re: Derivation

Note that I'm asking for 2nd law from first law not first from 2nd

3. Jul 25, 2012

### xAxis

Re: Derivation

I don't think so. The first Newtons Law just states that body will continue to move in a streight line unifiormly unless force acts on it.
Second Law quantitatively describes how exactly the velocity changes under the influence of force.

4. Jul 25, 2012

### Nstraw

Re: Derivation

Thanks. Well what do you think is the second law really the real law

5. Jul 26, 2012

### sankalpmittal

Re: Derivation

Yup , we say that Newton's second law is real law of motion because Newton's first law and third law may be derived using his second law. However doing converse isn't possible.

So you cannot derive Newton's second law from the first. However doing converse is possible , i.e. first law can be derived from second law.

6. Jul 26, 2012

### truesearch

Re: Derivation

Newton's first law states that an object will be either at rest or moving with constant velocity ( constant speed in a straight line) if there is no resultant ( unbalanced) force acting on it.
If there is a resultant force acting then the object cannot be at rest or moving with constant velocity which means that it must be accelerating.
So the first law tells you, qualitatively , that a resultant force causes acceleration.

7. Jul 26, 2012

### Nstraw

Re: Derivation

I understand now. Thank you all