- A fancy word for rotation or rotational.
- Centrifugal Force
- A non existent force which is actually the absence of a centripetal force.
- Centripetal Force
- A center seeking net force that is required to keep moving objects in a circular path.
If the requirement is not met, then objects move into larger curved paths or go off
on a tangent as they follow Newton's First Law.
- Driving Forces
- Forces that try to cause motion: In the case of falling it would be
gravity (weight). In the case of a car it would be the force from the engine
(through the friction on tires). Sometimes an object can have multiple driving
forces. (ie. an airplane in a dive, has the engine pushing it down at the same time
gravity is pulling it down)
- Fluid Friction
- Fluid friction differs from contact friction because the amount of fluid
friction depends on how fast the object is moving through the fluid. The greater the
speed, the greater the friction. This can be felt if you are in a pool of
water. Trying to walk from one side of the pool to the other is much easier than
trying to run. That's because the faster you move, the harder the fluid pushes against
you. When you examine contact friction you find that speed has no effect on the
amount of kinetic friction.
- The product of average net force and change in time. It can be
measured in NewtonSeconds (Ns) and is equal to (causes) the change in momentum.
- A fancy word meaning line like or along a line.
- Newton's First Law (The Law of Inertia)
- In the absence of a net force, an object will continue with its present
velocity. If it is at rest, it will stay at rest. If it is moving, it will
maintain its velocity (both magnitude and direction).
- Pressure is the result of Force divided by the Area the force is applied
over. It is measured in Newtons per meter squared [N/m2] which is also
known as a Pascal [Pa].
- Resistive Forces
- The forces that try to resist motion. The force of fluid friction
(from a liquid or gas) plays the main role in creating terminal velocity.
- Terminal Velocity
- The velocity at which the driving forces are cancelled out by the
resistive forces. Terminal velocity depends a great deal upon the shape of the
object that is facing the direction it is moving. Once an object has reached terminal
velocity, the object is not accelerating (a=0), therefore it is not speeding up or slowing
down. It is a constant velocity unless the driving forces or the resistive forces change.
Typically, Terminal Velocity is only a possibility when you are dealing with fluid
friction as opposed to contact friction like static or kinetic friction.