I have to guess either gravity or friction.
If by that you mean a force that opposes the start of motion, then your force would be static friction.
Static friction only occurs before an object starts moving, as opposed to kinetic friction which occurs when the objects is moving or sliding. The equation for static friction is: Ff = (coefficient of static friction) * FN
Inertia
Inertia
Friction. Specifically, static friction. After the object begins to move, it will still be necessary to overcome rolling or sliding friction to keep it in motion.
You must overcome static friction.
If the combined force is enough to overcome the force of friction, the desk will start moving.
Static Friction
Inertia
Sticky friction.
Unbalanced force is a type of force that causes an object to start moving.
Friction. Specifically, static friction. After the object begins to move, it will still be necessary to overcome rolling or sliding friction to keep it in motion.
You must overcome static friction.
If the combined force is enough to overcome the force of friction, the desk will start moving.
Static Friction
To make an object start moving is called acceleration, and it is done by exerting force on that object.
a force and inertia
Inertia
I have to guess either gravity or friction.If by that you mean a force that opposes the start of motion, then your force would be static friction.Static friction only occurs before an object starts moving, as opposed to kinetic friction which occurs when the objects is moving or sliding. The equation for static friction is: Ff = (coefficient of static friction) * FNInertia
The best, purest answer is: Because no force at all is required to keep a moving object moving.