Acceleration and Newton's 3 Laws of Motion Flashcards
What is acceleration?
The change in velocity per unit of time.
Acceleration =
Final Velocity – Initial Velocity / Time
Vf =
Final means finish or ending.
Vi =
Initial means start or beginning.
Acceleration includes one or more of:
1) increasing speed
2) decreasing speed
3) changing direction
Examples of acceleration:
- A car accelerating (speeding up) from a stoplight.
- A jet plane decelerating (slowing down) as it lands.
- A car going around a sharp curve. (changing direction)
Acceleration fact #1:
To find acceleration, the change in velocity during each unit of time must be calculated! (subtract the velocities, then divide by the time)
Acceleration fact #2:
The units for acceleration problems include a unit for the velocity change, and a unit for time.
A = Vf – Vi
———
T
m/day/hour
A positive number means it’s:
speeding up
A negative number means it’s:
slowing down
Galileo investigated:
force and motion
What is inertia?
The tendency of an object to resist changes in motion.
N1LOM fact #1:
Objects want to keep doing what they are doing, even if they’re standing still… doing nothing!
Example of N1LOM:
A writer being strong from a galloping horse AFTER the horse suddenly stops.
REMEMBER - before the sudden stop, the rider and the horse are moving together as one object. After the horse suddenly stops, the rider wants to keep moving forward.
Newton’s 1st Law of Motion =
the Law of Inertia
What is the Law of Inertia/Newton’s 1st Law of Motion?
an object at rest or in motion will stay at rest or in motion until acted on by another force.
N1LOM fact #2:
The heavier and object is, the more inertia it has.
What is Newton’s 3rd Law of Motion?
For every action, there’s an equal and opposite reaction.
Newton’s 3rd Law has two parts:
The action (the first part), and the reaction (the 2nd part).
N3LOM fact #1:
The action part is an event that happens; the reaction is the part that occurs AFTER the action.
This is called an action/reaction pair.
N3LOM example:
IMAGINE A MODEL ROCKET LAUNCH
(action) rocket fumes, smoke, sparks and flames going downward (backwards).
(reaction) - model rocket itself going upwards (forwards).
What is Newton’s 2nd Law of Motion?
The net force of an object is equal to the product of its mass and it’s acceleration.
Force =
Mass x Acceleration
SI unit for Acceleration is…
m/s/s (meters per second squared)
SI unit for Force is…
the Newton (N)
SI unit for Mass is…
kg (kilogram)
1 N =
1 kg x 1 m/s/s
What is a Newton?
The amount of force needed to accelerate an object with a mass of 1 kg and an acceleration of 1 m/s/s.
N =
kg m/s/s
Acceleration =
Force / Mass
N2LOM fact #1:
The acceleration of an object depends on the force acting on the object and the object’s mass.
