Download Motion Review Notes - Ms. Guggenheimer`s Education Connection

Motion Review
Motion is a change in position relative to some fixed object or
place, measured by distance and time
Reference point: a place or object used for comparison to
determine if something is in motion (frame of reference)
The point from which movement is determined.
The reference point is stationary (not moving)
Speed: the distance an object moved (traveled) in a specific unit
of time
Speed = Distance
Time
Constant Speed: When something moves at the same speed
for several hours. The speed of the object does not change. To
calculate the constant speed you use the formula for speed
Speed = Distance
Time
Average Speed: is equal to the total distance traveled divided
by the total time for the trip. It takes into account all speeds
during a period of time
Velocity: describes the speed and direction of a moving object
(speed in a given direction). It gives the distance, time and the
direction of travel. An object is accelerating when there is a
change in it's velocity
Acceleration: The rate of change in the velocity and the time for
the change to occur
Acceleration involves a change in either speed or direction
Speed can increase or decrease
Decreasing speed is sometimes called deceleration or
negative acceleration
Direction change is a form of acceleration even if the speed does
not change
Examples are:
a gentle curve in a road
a ferris wheel
the moon revolving around the earth
Acceleration = final velocity - initial velocity
Time
Measured in 2 units of time
For example:
An eagle accelerates from 15 m/s to 22 m/s in 4 seconds. What
is the eagle's average acceleration?
Acceleration = Vf- Vi = 22 m/s - 15 m/s = 7m/s = 1.75 m/s/s =
1.75 m/s2
Time
4s
4s
Momentum: a property of all moving objects.
The momentum of an object is equal to it's mass times it's
velocity.
Momentum = Mass x Velocity
The Law of Conservation of Momentum states that
momentum may be transferred but may not be lost.
Therefore, the momentum of object 1 will equal the momentum
of object 2. Accordingly,
Mass (object 1) x velocity (object 1) = mass (object 2) x
velocity (object 2)
Newton's Laws of Motion
Newton's First Law of Motion:
An object will remain at rest or move at a constant speed in a
straight line unless it is acted on by an unbalanced force.
Inertia - the tendency of an object to remain at rest or in motion
Newton's Second Law of Motion:
The acceleration of an object depends on the mass of the object
and the size and direction of the force acting on it.
Unbalanced forces cause objects to accelerate.
This second law describes the relationship among force, mass
and acceleration.
Force = mass x acceleration (F = m x a)
Newton's Third Law of Motion:
For every Action Force, there is an equal and opposite
Reaction Force
Forces always act in pairs