How is velocity determined from a distance over time graph

The slope of a distance vs time graph represents velocity.

Explanation:

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.