Factor

Factor How Why
Sensitivity Use smaller scale Respond quickly
Area Huge / small area => motion Increase / decreases air or water resistance
Huge / small area => pressure Small / Huge pressure
Shape streamline Reduce air or water resistance

Mass Heavy Increase inertia, take longer time to stop
Light Low inertia, easier to handle
Density High Heavy
Low Light
Height High High center of mass, less stable
Low Low center of gravity, more stable
Force Balance Not moving or move at same speed in the same direction
Unbalanced Produce net force/ produce acceleration
Velocity High Can move faster / Produce high momentum
Low Move slower / Less momentum
Acceleration High Produce large force
Low Produce smaller force
Time Long / Short Smaller / Big impulsive force
Power High Complete the work in short interval of time / Produce huge force or thrust
Low Complete the work in long interval of time / Small force or thrust
Hardness Hard / Soft => Impulsive force Produce huge impulsive force / small impulsive force
Hard / Soft => Time of collision Short time of collision / Long time of collision
Bright / Dark surface Bright Reflect light and heat well
Dark Bad light and heat reflector
Smooth / Rough Surface Smooth Smaller friction
Rough Big friction
Friction High Generate heat and spoil the machine
Low Can move faster
Strength of material High Can withstand huge force without breaking
Low Can bend the object easily / Break the object easily.