Download Acceleration - Weber Online

Welcome to Weber Physics Online
• This power point will help give you a basic
start to understanding the laws of physics and
it will also list the Utah State Physics Standards
and vocabulary to aid in your instruction.
(vocabulary will be bolded on the core outline)
• Remember this is a basic power point so feel
free to look at other sources for additional
information.(internet, books, movies etc.)
Utah State Core Standard
Objective 2: Using Newton’s second law, relate the
force, mass, and acceleration of an object.
• 1.Determine the relationship between the net force on
an object and the object’s acceleration.
• 2.Relate the effect of an object’s mass to its
acceleration when an unbalanced force is applied.
• 3.Determine the relationship between force, mass, and
acceleration from experimental data and compare the
results to Newton’s second law.
• 4.Predict the combined effect of multiple forces (e.g.,
friction, gravity, and normal forces) on an object’s
motion.
Newton’s 2nd Law
Discussion of Acceleration
Newton’s 2nd Law
• Acceleration is change in velocity / time
interval
• Unbalanced forces cause acceleration
• Increasing net force increases acceleration
proportionally
• Acceleration ~ net force
Relationship between mass and
acceleration
• Increasing mass decreases acceleration
• More massive objects require more force to
accelerate them
• Inverse relationship. Acceleration ~ 1 / mass
Newton’s 2nd Law
• Combines both effect of force and effect of
mass on acceleration
• States: Acceleration produced by net force is
directly proportional to magnitude of net
force, is in direction of net force, and is
inversely proportional to mass of object
• Acceleration = net force / mass
Solve this Problem
Mass = 5 kg
Let’s assume that the wheels of a 5kg car apply 10 N of force. What is
the net force if friction and drag are
negligible?
What is the acceleration of the car? Force = MA
10 = 5A
Acceleration =
Solve this Problem
Mass = 6 kg
What is the net force if the wheels of
the 5-kg car apply 10 but a 1-kg
parachute applies 3 in the other
direction?
Acceleration = F/M
What is the acceleration of the car?
Acceleration = 3/6
Acceleration =
Solve This One
Mass = 10 kg
A rocket is added to the car and applies an
additional force of 10 . The wheels still apply 10 N.
What is the net force if the parachute continues to
apply 7 in the other direction? The total mass of the
car, rocket and parachute is 10 kg.
Acceleration = F/M
What is the acceleration of the car?
Acceleration =13/10
Acceleration =
Free Fall
• In free fall, more massive objects experience
more force from gravity than smaller objects
• So F / m =
F/m
Terminal Velocity
• Downward pull of gravity = upward push of air
resistance
• Acceleration = 0
• Net force = 0
• Velocity is constant
Free fall and Terminal Velocity