Understanding Newton's Third Law - Physics
Card 0 of 64
If a tennis ball hits a racket with 
of force, what is the force of the racket on the ball?
If a tennis ball hits a racket with
Newton's third law states that every force has an equal and opposite force.
That means that 
. Since the force of the ball equals 
, the force of the racket must be equal and opposite.
.
Remember, this force will be negative as it is equal and OPPOSITE. That means it is moving in the opposite direction.
Newton's third law states that every force has an equal and opposite force.
That means that
Remember, this force will be negative as it is equal and OPPOSITE. That means it is moving in the opposite direction.
Compare your answer with the correct one above
A bat hits a baseball with 
of force. How much force does the baseball exert on the bat?
A bat hits a baseball with
Newton's third law states that when object A exerts a force on object B, object B exerts a force equal in magnitude but opposite in direction on object A.
That means that if the force of the bat on the ball is 
, then the ball on the bat must be 
.
Newton's third law states that when object A exerts a force on object B, object B exerts a force equal in magnitude but opposite in direction on object A.
That means that if the force of the bat on the ball is
Compare your answer with the correct one above
A hammer strikes a nail with 
newtons of force. How much force does the nail exert on the hammer?
A hammer strikes a nail with
Newton's third law states that for every force, there is an equal and opposite force. The force of the hammer on the nail will be equal in magnitude, but opposite in direction, to the force of the nail on the hammer.
Mathematically, that would mean 
.
The nail would exert 
force on the hammer.
Newton's third law states that for every force, there is an equal and opposite force. The force of the hammer on the nail will be equal in magnitude, but opposite in direction, to the force of the nail on the hammer.
Mathematically, that would mean
The nail would exert
Compare your answer with the correct one above
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of 
and an acceleration of 
, what is the mass of the other skater if her acceleration is 
?
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the acceleration of each skater and the mass of the first. Using these values, we can solve for the mass of the second.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector. From here, we need to isolate the mass of the second skater.
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the acceleration of each skater and the mass of the first. Using these values, we can solve for the mass of the second.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector. From here, we need to isolate the mass of the second skater.
Compare your answer with the correct one above
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of 
and an acceleration of 
, what is the acceleration of the other skater if her mass is 
?
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the mass of each skater and the acceleration of the first. Using these values, we can solve for the acceleration of the second.
From here, we need to isolate the acceleration of the second skater.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector.
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the mass of each skater and the acceleration of the first. Using these values, we can solve for the acceleration of the second.
From here, we need to isolate the acceleration of the second skater.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector.
Compare your answer with the correct one above
A rock strikes a window with 
of force. How much force does that window exert on the rock?
A rock strikes a window with
Newton's third law states that when one body exerts a force on another body, the second body exerts a force equal in magnitude, but opposite in direction, on the first body.
Mathematically, this process can be written as:
Since the rock exerts 
of force on the window, then the window must exert 
of force on the rock.
Newton's third law states that when one body exerts a force on another body, the second body exerts a force equal in magnitude, but opposite in direction, on the first body.
Mathematically, this process can be written as:
Since the rock exerts
Compare your answer with the correct one above
A boy falls out of a tree and hits the ground with 
of force. How much force does the ground exert on the boy?
A boy falls out of a tree and hits the ground with
Newton's third law states that when one object exerts a force on another object, that second object exerts a force of equal magnitude, but opposite in direction on the first.
That means that:
Using the value from the question, we can find the force of the ground on the boy.
Newton's third law states that when one object exerts a force on another object, that second object exerts a force of equal magnitude, but opposite in direction on the first.
That means that:
Using the value from the question, we can find the force of the ground on the boy.
Compare your answer with the correct one above
A hunter fires a rifle. The rifle kicks back with 
of force. How much force does the hunter's shoulder exert on the rifle during kick back?
A hunter fires a rifle. The rifle kicks back with
If the rifle exerts a force of 
on the hunter's shoulder, then the hunter's shoulder will exert 
of force on the rifle.
This is because of Newton's third law, which states that when one object exerts a force upon another object, the second object exerts a force equal in magnitude but opposite in direction to the first force. Mathematically that means 
. Since our first force was 
, the second force will be 
.
If the rifle exerts a force of
This is because of Newton's third law, which states that when one object exerts a force upon another object, the second object exerts a force equal in magnitude but opposite in direction to the first force. Mathematically that means
Compare your answer with the correct one above
Which of Newton's laws explains why it is easy for you to lift a 1L jug of milk from the fridge, but impossible to lift a 1000L jug?
Which of Newton's laws explains why it is easy for you to lift a 1L jug of milk from the fridge, but impossible to lift a 1000L jug?
The answer is more than one. The two laws that come into play are Newton's first and second laws. Newton's first law is best known as the law of inertia. It states that an object in motion will stay in motion and an object at rest will stay at rest unless acted on by an outside force. Newton's second law relates the acceleration of an object to the mass and the forces acting on it with the equation 
. An object won't move or stop moving unless the forces acting on it are imbalanced. In the case of the milk jug, it remained at rest until an outside force, your hand, acted upon it, demonstrating Newton's first law. The second law is applicable because the amount of acceleration of the two milk jugs is inversely related to their mass. It takes a much stronger force to move the 1000L milk jug than it does the 1L milk jug. The acceleration is also much smaller for the two objects when the same force is applied because one weighs so much more than the other. You can visualize this by rearranging the second law equation: 
. It is also beneficial to think in terms of two objects. Which is will accelerate more when you try and move it with the same force, a tennis ball or an elephant?
The answer is more than one. The two laws that come into play are Newton's first and second laws. Newton's first law is best known as the law of inertia. It states that an object in motion will stay in motion and an object at rest will stay at rest unless acted on by an outside force. Newton's second law relates the acceleration of an object to the mass and the forces acting on it with the equation
Compare your answer with the correct one above
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of 
and an acceleration of 
, what is the acceleration of the other skater if her mass is 
?
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of 
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the mass of each skater and the acceleration of the first. Using these values, we can solve for the acceleration of the second.
From here, we need to isolate the acceleration of the second skater.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector.
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the mass of each skater and the acceleration of the first. Using these values, we can solve for the acceleration of the second.
From here, we need to isolate the acceleration of the second skater.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector.
Compare your answer with the correct one above
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of 
and an acceleration of 
, what is the mass of the other skater if her acceleration is 
?
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of 
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the acceleration of each skater and the mass of the first. Using these values, we can solve for the mass of the second.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector. From here, we need to isolate the mass of the second skater.
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the acceleration of each skater and the mass of the first. Using these values, we can solve for the mass of the second.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector. From here, we need to isolate the mass of the second skater.
Compare your answer with the correct one above
Basic Computational
A rock strikes a window with 
of force. How much force does that window exert on the rock?
Basic Computational
A rock strikes a window with 
Newton's third law states that when one body exerts a force on another body, the second body exerts a force equal in magnitude, but opposite in direction, on the first body.
Mathematically, this process can be written as:
Since the rock exerts 
of force on the window, then the window must exert 
of force on the rock.
Newton's third law states that when one body exerts a force on another body, the second body exerts a force equal in magnitude, but opposite in direction, on the first body.
Mathematically, this process can be written as:
Since the rock exerts 
Compare your answer with the correct one above
A boy falls out of a tree and hits the ground with 
of force. How much force does the ground exert on the boy?
A boy falls out of a tree and hits the ground with 
Newton's third law states that when one object exerts a force on another object, that second object exerts a force of equal magnitude, but opposite in direction on the first.
That means that:
Using the value from the question, we can find the force of the ground on the boy.
Newton's third law states that when one object exerts a force on another object, that second object exerts a force of equal magnitude, but opposite in direction on the first.
That means that:
Using the value from the question, we can find the force of the ground on the boy.
Compare your answer with the correct one above
Conceptual
If you exert a force F on an object, the force which the object exerts on you will
Conceptual
If you exert a force F on an object, the force which the object exerts on you will
According to Newton’s 3rd Law of Motion, the force that is exert by object A onto object B is equal in magnitude and opposite in direction to the force that is exerted by object B onto object A. It is not dependent on the mass or motion of the object.
According to Newton’s 3rd Law of Motion, the force that is exert by object A onto object B is equal in magnitude and opposite in direction to the force that is exerted by object B onto object A. It is not dependent on the mass or motion of the object.
Compare your answer with the correct one above
An object of mass m sits on a flat table. The Earth pulls on the object with force mg, which is the action force. What is the reaction force?
An object of mass m sits on a flat table. The Earth pulls on the object with force mg, which is the action force. What is the reaction force?
There is a common misconception that the force that Earth pulls on the object is balanced by a reaction force of the table pushing up on the object. Though it is true that the magnitude between these forces are the same, they are not considered action reaction pairs.
According to Newton’s 3rd law the force with which object A acts on object B is equal and opposite to the force that object B acts on object A. In this case the initial force is the Earth pulling on the object. Therefore the pair would be the object pulling on the Earth.
If we consider the table we are adding a third object to the mix, which cannot be an action reaction pair. Therefore the normal force and the force of gravity are never considered action reaction pairs as they are two different forces acting on the same object.
There is a common misconception that the force that Earth pulls on the object is balanced by a reaction force of the table pushing up on the object. Though it is true that the magnitude between these forces are the same, they are not considered action reaction pairs.
According to Newton’s 3rd law the force with which object A acts on object B is equal and opposite to the force that object B acts on object A. In this case the initial force is the Earth pulling on the object. Therefore the pair would be the object pulling on the Earth.
If we consider the table we are adding a third object to the mix, which cannot be an action reaction pair. Therefore the normal force and the force of gravity are never considered action reaction pairs as they are two different forces acting on the same object.
Compare your answer with the correct one above
A ball is suspended from the ceiling by means of string. The Earth pulls downward on the ball with its weight force of 
. If this is the action force, what is the reaction force?
A ball is suspended from the ceiling by means of string. The Earth pulls downward on the ball with its weight force of 
There is a common misconception that the force that Earth pulls on the object is balanced by a reaction force of the string pulling upward on the object. Though it is true that the magnitude between these forces are the same, they are not considered action reaction pairs.
According to Newton’s 3rd law the force with which object A acts on object B is equal and opposite to the force that object B acts on object A. In this case the initial force is the Earth pulling on the object. Therefore the pair would be the object pulling on the Earth.
If we consider the table we are adding a third object to the mix, which cannot be an action reaction pair. Therefore the tension force and the force of gravity are never considered action reaction pairs as they are two different forces acting on the same object.
There is a common misconception that the force that Earth pulls on the object is balanced by a reaction force of the string pulling upward on the object. Though it is true that the magnitude between these forces are the same, they are not considered action reaction pairs.
According to Newton’s 3rd law the force with which object A acts on object B is equal and opposite to the force that object B acts on object A. In this case the initial force is the Earth pulling on the object. Therefore the pair would be the object pulling on the Earth.
If we consider the table we are adding a third object to the mix, which cannot be an action reaction pair. Therefore the tension force and the force of gravity are never considered action reaction pairs as they are two different forces acting on the same object.
Compare your answer with the correct one above
If a tennis ball hits a racket with of force, what is the force of the racket on the ball?
If a tennis ball hits a racket with
Newton's third law states that every force has an equal and opposite force.
That means that . Since the force of the ball equals , the force of the racket must be equal and opposite.
.
Remember, this force will be negative as it is equal and OPPOSITE. That means it is moving in the opposite direction.
Newton's third law states that every force has an equal and opposite force.
That means that
Remember, this force will be negative as it is equal and OPPOSITE. That means it is moving in the opposite direction.
Compare your answer with the correct one above
A bat hits a baseball with of force. How much force does the baseball exert on the bat?
A bat hits a baseball with
Newton's third law states that when object A exerts a force on object B, object B exerts a force equal in magnitude but opposite in direction on object A.
That means that if the force of the bat on the ball is , then the ball on the bat must be .
Newton's third law states that when object A exerts a force on object B, object B exerts a force equal in magnitude but opposite in direction on object A.
That means that if the force of the bat on the ball is
Compare your answer with the correct one above
A hammer strikes a nail with newtons of force. How much force does the nail exert on the hammer?
A hammer strikes a nail with
Newton's third law states that for every force, there is an equal and opposite force. The force of the hammer on the nail will be equal in magnitude, but opposite in direction, to the force of the nail on the hammer.
Mathematically, that would mean .
The nail would exert force on the hammer.
Newton's third law states that for every force, there is an equal and opposite force. The force of the hammer on the nail will be equal in magnitude, but opposite in direction, to the force of the nail on the hammer.
Mathematically, that would mean
The nail would exert
Compare your answer with the correct one above
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of and an acceleration of , what is the mass of the other skater if her acceleration is ?
Two skaters push off of each other in the middle of an ice rink. If one skater has a mass of
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the acceleration of each skater and the mass of the first. Using these values, we can solve for the mass of the second.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector. From here, we need to isolate the mass of the second skater.
For this problem, we'll use Newton's third law, which states that for every force there will be another force equal in magnitude, but opposite in direction.
This means that the force of the first skater on the second will be equal in magnitude, but opposite in direction:
Use Newton's second law to expand this equation.
We are given the acceleration of each skater and the mass of the first. Using these values, we can solve for the mass of the second.
Notice that the acceleration of the second skater is negative. Since she is moving in the opposite direction of the first skater, one acceleration will be positive while the other will be negative as acceleration is a vector. From here, we need to isolate the mass of the second skater.
Compare your answer with the correct one above