Absolutely the most helpful website to learn

Hyper Physics http://hyperphysics.phy-astr.gsu.edu/hbase/index.html#mechcon 

Key definitions

Vectors  - a line with direction and magnitude (a value of force, velocity, etc)  

Mass (M) - The quantity of matter (stuff) that holds something together

• Measured in grams (g) for metric

• Measured in pounds (lb)

Distance (d) - The measure of space traversed. 

• For linearly moving bodies this is measured in: 

  • Meters (m) for metric 

  • Inches (in) and feet (ft)

• For rotating bodies this is measured by angles in:

  • Degrees (0 - 360) (°)

  • Radians (0 - 2π) (r/rads)

  • Rotations/revolutions (a movement of a full 360 degrees or 2π)

Time (t) -  A measurable period

• Measured in seconds (s)

• Measured in minutes (m)

Velocity (v) - The amount of distance traveled over a period of time (this is the vector value for how fast a body moves, so it has direction)  

• Defined as: V = d / t - velocity equals distance over time 

• For linearly moving bodies:

  • Measured in meters per second (m/s)

  • Measured in feet per second (ft/s)

  • Measured in feet per minute (ft/m)

• For rotating bodies:

  • Measured in rotations per minute (RPM)

  • Measured in radians per second (rads/s)

Acceleration (a) - The change in velocity over a period of time

• Defined as: A = v / t

• For linearly moving bodies:

  • Measured in meters per second squared (m/s^2)

  • Measured in feet per second squared (ft/s^2)

• For rotating bodies:

  • Measured in radians per second squared (rads/s^2)

Force (F) - An influence that causes a body to accelerate. Can be a push or a pull. Has direction and magnitude. 

• Defined as: F = m * a

• Measured in newtons (n)

• Measured in pound-force (lbf)

Energy - The capacity for work to be done. Measured in joules. Cannot be created or destroyed.

Work - The amount of force exhibited over a distance. The amount of transferred kinetic energy. Typically used for forces that induce translational/linear movement

• Defined as Work = F * d

  • Measured in newton-meters (nm)

  • Measured in joules (j)

  • Measured in foot-pounds (ft*lbf)

Moment - Same as work but in reference for forces that have the tendency to induce rotation

• Same units as work

• BUT defined as the perpendicular distance from a center axis of rotation to a downward force

Torque - A moment that measures the force of a rotating body

• Same as moment in simple terms

Power (P) - The amount of work that can be done over time

• Defined as P = Work / time

  • Measured in watts (w - equals j/t)

  • Measured in foot-pounds per second ((ft * lbf)/s) 

  • Measured in horsepower (hp - equals ((ft * lbf)/s) / 550 ((ft*lbf)/s)

  • For rotating bodies this is Torque * RPM

Note on weight* 

• Weight is the force resulting from an object's mass times the acceleration due to gravity (9.81m/s^2). On Earth mass and weight are interchangeable for most of the math we'll be doing.

• Technically measured in newtons and pounds-force