Newtons Third Law and Force Imbalance

In summary, the statement that accurately describes the scenario is that according to Newton's third law, the forces exerted by the two men on each other are always equal and opposite, but the smaller man moves backwards because the net force on him is greater than zero due to the force of friction being overcome.
  • #1
narutodemonki
7
0

Homework Statement


1.A 140 kg man pushes a 90 kg man. They are first motionless, as they push larger man moves smaller one backwards.
which statement is correct.
a)forces are always equal
b) larger wrestles always exerts larger force
c)when they are motionlesss forces are equal but as they start to move larger man exerts a larger force on smaller man exert man on him.


The Attempt at a Solution


According to Newtons third law..every action force has an equal but pposite reaction force
..in that case the answer would be a)
but than why is the smaller man moving back is it because the force of friction on the man has been overcome?
 
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  • #2
According to Newtons third law..every action force has an equal but opposite reaction force
..in that case the answer would be a)
Yes, you are correct, but I think the problem should have been worded better: the force exerted by the larger man on the smaller man is always equal (and opposite) to the force exerted by the smaller man on the larger man.
but than why is the smaller man moving back is it because the force of friction on the smaller man has been overcome?
Yes, the net force on the smaller man is greater than zero, so the smaller man accelerates, per Newton 2; the net force on the larger man is zero, so the larger man does not move, per Newton 1.
 

Related to Newtons Third Law and Force Imbalance

1. What are Newton's three laws of motion?

Newton's first law of motion states that an object at rest will remain at rest and an object in motion will remain in motion at a constant velocity unless acted upon by an external force. Newton's second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Newton's third law of motion states that for every action, there is an equal and opposite reaction.

2. How do Newton's laws of motion apply to everyday life?

Newton's laws of motion can be observed in everyday life. For example, a person sitting in a chair represents Newton's first law as the person will remain at rest until they are acted upon by an external force, such as standing up. Another example is a ball rolling down a hill, which demonstrates Newton's second law as the ball accelerates due to the force of gravity and the slope of the hill. Newton's third law can be observed when a person jumps off a diving board, as the force pushing down on the board is equal and opposite to the force propelling the person upwards.

3. How did Newton develop his laws of motion?

Isaac Newton developed his laws of motion through a combination of observations, experiments, and mathematical calculations. He observed the motions of objects in the natural world and conducted experiments to test his theories. He also used mathematical equations, such as his famous equation F=ma, to describe the relationship between force, mass, and acceleration.

4. Are there any exceptions to Newton's laws of motion?

While Newton's laws of motion are accurate in most situations, there are some exceptions. In the realm of quantum mechanics, the laws of motion do not always apply as particles can be in multiple places at once and can have varying degrees of mass. At extremely high speeds, such as those approaching the speed of light, the laws of motion also break down and are replaced by Albert Einstein's theory of relativity.

5. How are Newton's laws of motion related to other scientific principles?

Newton's laws of motion are closely related to other scientific principles, such as conservation of energy and momentum. Newton's laws also play a role in understanding concepts such as gravity and friction. These laws are also fundamental to the study of mechanics and have been expanded upon and applied in various fields of science, such as engineering, astronomy, and biology.

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