Kinetic Energy

Kinetic Energy is the energy available if an object moving at a constant velocity is brought to rest.  It is also the energy needed to move an object from rest to a constant velocity.

The total Kinetic Energy of a rolling body is:

  • The equation for a wheel rolling down a ramp is:

  • When the inertial value for a wheel is inserted for I, and an equivalent value is substituted for the angular velocity  , the radius factors cancel and the mass factors cancel and the solution for the linear velocity v will be independent of mass or radius.

wheel rolling down a ramp



Work is the change in Kinetic Energy, or torque applied over a moving angle or force applied over a distance. 


Instantaneous Power is defined as the time rate of doing work.  

Air Resistance

The resistance from moving at speed through the air.



The Force of friction is the resistance to sliding motion along the line of surface contact between two objects.  Static friction is the force when no sliding happens.  Kinetic friction is the force when the two surfaces slide in relation to each other.

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