Why Do Objects Move Despite Equal and Opposite Reactions?

AI Thread Summary
Newton's third law states that for every action, there is an equal and opposite reaction, but this does not prevent movement because forces act on different objects. For example, when pushing a box, the box exerts an equal force back, but it can still accelerate if no opposing force acts on it from another direction. Similarly, when swimming, kicking against the water propels the swimmer forward as the water pushes back. The key point is that the forces involved are applied to separate bodies, allowing for movement despite the law's implications. Understanding this distinction clarifies how objects can still move in response to applied forces.
Dirtyhand
Messages
1
Reaction score
0
It says that every reaction there is a opposite and equal reaction. Why do things still move if everything is opposite and equal?
 
Science news on Phys.org
Basically, objects are independent of each other, i think you are thinking of them as a system
Example: I push on a BOX. The box pushes back on ME. Something else does not push from the opposite side of the box to balance my push. The box experiences an unbalanced force and possibly accelerates.
 
to put it a different way, the forces act on different objects.
think of you swimming... you kick back your legs against the water, applying force on it by pushing it backwards, but by Newtons third law, the water will push back on you. The end result being that you get pushed forward by the water, and hence, move forward, and the water gets pushed back by your feet...
 
Dirtyhand said:
It says that every reaction there is a opposite and equal reaction. Why do things still move if everything is opposite and equal?

Don't confuse Newton's third law with the second.

http://en.wikipedia.org/wiki/Newton's_laws_of_motion
 
Dirtyhand said:
It says that every reaction there is a opposite and equal reaction. Why do things still move if everything is opposite and equal?

The forces are applied to different bodies.
 
Last edited:

Thread 'Condensate rate of water for an air conditioning cooling coil'

I need to calculate the amount of water condensed from a DX cooling coil per hour given the size of the expansion coil (the total condensing surface area), the incoming air temperature, the amount of air flow from the fan, the BTU capacity of the compressor and the incoming air humidity. There are lots of condenser calculators around but they all need the air flow and incoming and outgoing humidity and then give a total volume of condensed water but I need more than that. The size of the...
View full post »
Thread 'Why work is PdV and not (P+dP)dV in an isothermal process?'

Thread 'Why work is PdV and not (P+dP)dV in an isothermal process?'

Let's say we have a cylinder of volume V1 with a frictionless movable piston and some gas trapped inside with pressure P1 and temperature T1. On top of the piston lay some small pebbles that add weight and essentially create the pressure P1. Also the system is inside a reservoir of water that keeps its temperature constant at T1. The system is in equilibrium at V1, P1, T1. Now let's say i put another very small pebble on top of the piston (0,00001kg) and after some seconds the system...
View full post »

Similar threads

I Newton's Third Law: Action & Reaction Along the Line Connecting Two Objects
Replies
5
Views
1K
The violation of Newton's third Law
Replies
28
Views
4K
Opposing forces and Newton's third law
Replies
8
Views
4K
B Newton's Third Law in space
Replies
20
Views
2K
Trouble understanding Newton's Third Law in Pulleys
Replies
7
Views
6K
Why Does a Ball Bounce Back from a Wall But Not from Sand?
Replies
3
Views
2K
Newton's third law in relation to field forces
Replies
2
Views
2K
Center of mass, Newton's third law, and rocket thrust
Replies
8
Views
3K
How Does Newton's Third Law Clarify Force and Acceleration Misconceptions?
Replies
24
Views
3K
Newton's Third Law doesn't make sense
Replies
5
Views
9K

Hot Threads

Recent Insights

Back
Top