Question

define force and mention its si units

Answer 1

In physics, a force is any interaction that, when unopposed, will change the motion of an object.[1] A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vectorquantity. It is measured in the SI unit of newtons and represented by the symbol F.

Answer 2

Force is a push or pull of an object resulting in the object interaction with another object
It's SI unit is newton