Gravity
Gravity.
Friction between the desk and the floor acts as an unbalanced force to stop the desk from sliding. As the desk moves, the force of friction opposes the direction of its motion, eventually bringing it to a stop.
The normal force acting on a book sitting on a desk is equal in magnitude and opposite in direction to the force of gravity pulling the book downward. This force prevents the book from falling through the desk and is what keeps the book in place.
gravity, the one that keeps you falling down. or the electromagnetic force which keeps you from falling through the floor.
Gravity
The floor must exert a force equal to that of the force exerted on the desk from gravity. This force is called a "normal force"
Gravity is the force that causes the pen to fall from the desk to the floor when it rolls off. Gravity acts as an attractive force between objects with mass, pulling the pen towards the Earth's surface.
work would be done if the book fell from the top of the desk to the floor because there has been some force through which the book fell down and therefore the book got displaced from his initial position . hence the work is done in this situation because it has a force and a displacement which is essential for the work to be done.
No, an unbalanced desk is not an example of an unbalanced force. An unbalanced force refers to a force that causes motion or a change in motion, while an unbalanced desk is simply an object that is not level.
Yes, the force exerted by the floor on our feet is equal to the force that our feet exerted on the floor, or it just depends on your weight, If you are heavier than the normal. When you stand, the longer the time you stand, the more pain you feel on your feet. And we can't be move upward by the force that the floor exerted on our feet because of the force of our weight that keeps us on the ground, and also because of gravity.
frictional force which is generated due to interlocking of minute roughness of slipper / shoes/foot with those of floor
The force from your desk on an object placed on it is equal in magnitude and opposite in direction to the force that the object exerts on the desk due to Newton's third law of motion.