For the normal force exerted on the book by the wedge in the diagram, which force(s) complete(s) the force pair for Newton’s third law (action-reaction)?
1) the sum of the component of gravity perpendicular to the surface of the incline and the component of Fhand perpendicular to the surface of the incline
2) the pull of the earth on the book
3) the component of gravity pointing parallel to the surface of the incline
4) the component of Fhand pointing perpendicular to the surface of the incline
5) the normal force exerted on the wedge by the book
6) the pull of the book on the earth
7) the component of gravity pointing perpendicular to the surface of the incline
A
The force pair for Newton's third law consists of two forces that are equal in magnitude and opposite in direction.
In the given options, the forces that complete the force pair for the normal force exerted on the book by the wedge are:
1) the sum of the component of gravity perpendicular to the surface of the incline and the component of Fhand perpendicular to the surface of the incline
4) the component of Fhand pointing perpendicular to the surface of the incline
7) the component of gravity pointing perpendicular to the surface of the incline
Therefore, the correct answer is options 1), 4), and 7).
To determine which force(s) complete(s) the force pair for Newton’s third law, we need to think about the action-reaction pairs involved.
Newton's third law states that for every action, there is an equal and opposite reaction. In this case, we are looking for the force(s) that are equal and opposite to the normal force exerted on the book by the wedge.
The normal force exerted on an object is the perpendicular force exerted by a surface to support the weight of the object. It is always directed perpendicular to the surface.
So, to find the force(s) that complete(s) the force pair for the normal force exerted on the book by the wedge:
Option 2, the pull of the earth on the book, is not the force pair for the normal force exerted by the wedge. This force is the weight of the book, but it is not equal and opposite to the normal force.
Options 3 and 7, the component of gravity pointing parallel and perpendicular to the surface of the incline, respectively, are the gravitational forces acting on the book. These forces are not equal and opposite to the normal force exerted by the wedge.
Option 6, the pull of the book on the earth, is the force pair for the weight of the book, but it is not equal and opposite to the normal force exerted by the wedge.
Option 5, the normal force exerted on the wedge by the book, is not the force pair for the normal force exerted by the wedge on the book. This force is not equal and opposite to the normal force.
Therefore, the correct answer is option 4, the component of Fhand pointing perpendicular to the surface of the incline. This force is equal in magnitude and opposite in direction to the normal force exerted by the wedge on the book.