Newton's third law of motion states that ""FOR EVERY ACTION THERE IS EQUAL AND OPPOSITE REACTION"

Question

So my question is how a horse pull a cart?
i mean that if horse pulls the cart with some force forward so cart should also apply same amount of force in backward direction.(Newton's 3 law of motion)

Answer 1

Yes you are correct. The horse pulls the cart and the cart pulls the horse. The forces are equal and opposite.

To find how the horse or cart move,

Consider either horse or cart not both.

First let us consider the horse.

The horse is pulled back by the force exerted by the cart.

That means the horse should move backward.

But in practice we see it going in front.

There fore we must infer that there are some other forces are also acting on the horse.

When the horse pushes the ground with some force, the ground in turn pushes the horse in the opposite direction.

Thus there is a force given by the ground on the horse.

There are now two forces acting on the horse.

One force given by the cart that pulls it backward and another force given by the ground that acts forward.

If these two forces were equal and opposite, the horse will be at rest or will move with uniform speed.

If the forward force is greater than the cart’s back ward force, the horse will move with acceleration.

Now consider the cart.

The cart is pulled by the horse. The friction opposes it. If these two forces were equal and opposite, the cart will be at rest or will be in uniform speed. If the pulling force is greater than the frictional force then it will move with acceleration.

Note also that the frictional force cannot exceed the applied force.

Again consider the horse and cart as a single object. In that case we are not bothered about the internal forces.

Now the forces that act on this system are the force given by the ground on the horse due to reaction and the force due to friction.

The system moves with some acceleration or with uniform motion or at rest according to the net force acting on the system.

Answer 2

Guarantee you the Best Answer

To make the cart move ,the horse bends forward and pushes the ground with its feet.When the forward reaction to the backward push of the horse is greater then the opposing forces on the wheels,the cart moves.

Please note---It is only the force on the cart which determines whether the cart will move or not,and that the force exerted by the cart on the horse affects the horse alone.

Take Care
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Answer 3

Newton's Law

First law:. a body moving in space will continue to move in straight line unless deflected by another external force.

Second law: F = ma

Third law: Action = reaction


example of third law is the a suspended weight in a rope. action is the weight and reaction is the tension in the rope

your problem about the horse pulling a cart belongs to the second law.

the cart is acted by a force of the horse. For quite some time the cart is accelerated, in some of the time the force of friction will decelerate the car. So it seems the cart is just moving in constant velocity, but its not.
If you stop the pulling of the cart, the cart will decelerate and will stop on its own because of friction.

Answer 4

Because the cart experiences rolling friction with respect to the ground and the horse is exerting a forward force with respect to the ground. So, you need to take the friction between the horse and the ground as well as the cart's wheels and the ground into consideration.

If the horse and the cart were in empty space, the horse will not be able to pull the cart. A very slippery surface also offers very little purchase to the horse.

Answer 5

You need to consider the cart in isolation. Draw a free body diagram of just the cart. See link below. The backward reaction force you speak of is acting on the horse not the cart. To consider the horse you then draw a separate free body diagram of the horse with this reaction force which if the cart is to actually move must be overcome by a larger force between the horses hoofs and the ground.

A google search on "free body diagrams" gives several good tutorials on basic mechanics (the branch of physics that deals with these questions).

Answer 6

Actually, the Newton's Third Law of motion, which is "FOR EVERY ACTION THERE IS EQUAL AND OPPOSITE REACTION", cannot be applied at the horse pulling the cart.

And it is the, gravity and inertia of the cart that cause the force which counter acts the horse's pulling force.

It is actually Newton's First Law and Second Law of motion.
Second Law, Law of Acceleration: The changing of velocity on a given time
First Law, Law of Inertia: The ability of the object to resist other force.

The horse pulls the cart and the cart goes faster, so there is acceleration(Law of Acceleration)
The cart resist some of the horse's pulling force, so there is resistance(law of Inertia).

Answer 7

The horse exerts a force on the cart and the cart exerts an equal force on the horse.The forces exerted by each other are equal but since they are in the opposite the horse is able to pull the cart.

Answer 8

well a good question ,but you should change your viewpoint ,when a horse pulls a cart, the cart exerts an opposite force on him but there is another force acting on the horse and that is the force between the horse's feet and groud ,in fact this force makes the horse to move

Answer 9

THe opposite force is the force that the horse's legs apply to the ground when walking. For example, when you walk, your heel lifts and you press the front of your foot down and towards the back. Since the ground doesn't move you do, in the opposite direction (forward). This is Newton's law in effect.

Answer 10

think there is no cart,only horse is there.when horse put his first step forward then according to the newton's third law the action is pulling of the first leg and keeping it on the ground and the reaction is the pulling of the other leg.so,reaction is keeping the first leg on the ground and pulling of other leg.and the cart is joined to the horse and is the part of the horse and reaction takes place on different substance.