A book is resting on the table and not moving. Describe the forces acting on the book, and relate this to the fact that the book is at rest.
The forces acting on the book while it is at rest are balanced. The main force acting on the book is gravity, which is pulling the book downward towards the Earth. In order for the book to remain at rest on the table, there must be an equal and opposite force pushing upwards on the book called the normal force.
When the book is placed on the table, the table exerts an upwards normal force on the book that balances out the force of gravity pulling the book downwards. This balance of forces is why the book remains at rest on the table without moving.
In summary, the balanced forces of gravity pulling downwards and the normal force pushing upwards on the book result in the book being at rest on the table.
Why would a heavier object require a greater force to accelerate?
A heavier object requires a greater force to accelerate because of its greater inertia. Inertia is the tendency of an object to resist changes in its state of motion. The more mass an object has, the greater its inertia, meaning it requires a larger force to change its motion.
When a force is applied to an object to accelerate it, the object's inertia resists this change in motion. The greater the object's mass, the more inertia it has, and the more force is needed to overcome this resistance and accelerate the object.
This is why a heavier object requires a greater force to accelerate compared to a lighter object. The relationship between an object's mass, its inertia, and the force needed to accelerate it is described by Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.