Linked Questions

46
votes
3answers
17k views

If Newton's third law is true, why can we sink in sand? [duplicate]

Newton's third law of motion states that every action has an equal and opposite reaction. That is the reason we do not sink into the earth, because when our weight exerts a force on the earth it also ...
15
votes
14answers
30k views

Is Newton's third law always correct?

Newton's third law states that every force has an equal and opposite reaction. But this doesn't seem like the case in the following scenario: For example, a person punches a wall and the wall breaks. ...
11
votes
3answers
11k views

How does the force of tension really work?

I am currently studying high school physics (I'm in the first year of high school). The force of tension initially seemed to be a simple concept, but unfortunately has proved rather challenging to ...
6
votes
3answers
7k views

Why does the cart move? [duplicate]

A while ago someone proposed the following thought experiment to me: A horse attached to a cart is resting on a horizontal road. If the horse attempts to move by pulling the cart, according to the ...
6
votes
5answers
5k views

How can a car's engine move the car?

Newton's First Law of Motion states that an object at rest or uniform motion tends to stay in that state of motion unless an unbalanced, external force acts on it. Say if I were in a car and I push ...
4
votes
5answers
63k views

If something that is moving at constant velocity has no net force acting on it, how come it is able to move other objects?

Let's say 10 kg block is sliding on a frictionless surface at a constant velocity, thus its acceleration is 0. According to Newton's second law of motion, the force acting on the block is 0: $a = 0$...
3
votes
4answers
232 views

Force (Newton's third law of motion) [duplicate]

When we apply a force, there's always a reaction force too. Why do forces always come in pairs?
3
votes
1answer
2k views

How muscle force work? [closed]

If muscle works with force on joint and joint works with exact force on muscle(newton III law) how can muscle drag much heavier weight than itself?
3
votes
4answers
3k views

Work done by the piston versus work done by the surrounding

Suppose a massless, frictionless piston assembly initially has a higher pressure than the external (atmospheric) pressure, and it is pinned so that the piston does not move. Once the pin is removed, ...
2
votes
4answers
2k views

Newton's Third Law of Motion

I want to start off by saying that I've looked around for other explanations, but I've not really found any satisfying ones. My question is basically the whole "Why can anything move at all?" question,...
2
votes
3answers
205 views

How does the Earth bring down a falling object's velocity to zero on contact?

How does the earth bring down a falling object's velocity to zero on contact? If the normal force on an object from a horizontal surface is equal to the weight of the object, the object could never ...
2
votes
2answers
936 views

Newton's third law confusions [duplicate]

According to Newton's third law of motion, if body A exerts a force on body B, then body B exerts a force on body A that is equal in size but opposite in direction, then how do things move?
2
votes
1answer
1k views

How can I actually push heavier objects?

I've been thinking about Newton's third law lately because I couldn't understand a few things and I think I actually answered my own question. Could someone confirm if my reasoning is right or show me ...
2
votes
3answers
209 views

Information about newton's third law

Well I am still small student of physics, but as far as I know, Newton's Third Law states that, "For every action there is equal and opposite reaction." Now let me tell you how I understood this, ...
2
votes
2answers
185 views

Force balancing - Newtonian mechanics [duplicate]

If a horse pulls the carriage, the carriage should pull the horse with equal force (Newton's third law), then how does the whole system move? I drew the free body diagram but not yet figured what ...

15 30 50 per page