Earth's acceleration due to gravity explained

Velocity changes over time due to acceleration of gravity- FreeScienceStuff

Terminal velocity - Phillips Physics

Terminal velocity is reached when the force of acceleration equals the force of resistance in the form of drag. Gravity produces an acceleration of 9.8 meters/second/second or 9.8 meters/second squared.

Acceleration due to gravity - 1 min.

Objects regardless of mass fall at the same rate due to gravitational acceleration assuming that the resistance of drag is the same for both objects. 

Which hits the ground first - 3 min.

Speed versus Velocity

Weebly.com speed vs velocity

Speed is a scalar quantity in distance per unit of time without specifying direction.  Velocity is a vector quantity in distance per unit of time with a direction.

Examples. 

• Speed: A car travels 40 miles per hour.
• Velocity: A car travels 40 miles per hour traveling south.

Speed vs. Velocity 3 min. David Hart Physics