Download Motion

MOTION
SPEED, VELOCITY, ACCELERATION, GRAVITY
& NEWTON’S LAWS
MASS & WEIGHT
• Mass – the amount of matter in an object
• Will not change according to location
• Weight – measures the gravitational pull on an object
• Depends on gravity, since different planets have different
amounts of gravity, so the weight of objects will change on
different planets.
SPEED & VELOCITY
• Speed – the amount of time it takes an object to travel a certain distance
• Formula – S= D
T
• EX : Josh runs 3 miles in 30 minutes. What is his speed?
3 miles
= .10 miles/minute
30 minutes
• Velocity – speed of an object in a specific direction.
• Formula – use the formula for speed but be sure to include the
direction
• EX: William drives his car 300 miles from Georgia to Florida. It takes him
5 hours. What was his velocity?
300 miles
5 hours
= 6 miles/hour
ACCELERATION
• Acceleration is a change in
speed or direction
• An object is accelerating if it:
speeds up, slows down, or
changes directions
• Positive acceleration – when an
object speeds up
• Negative acceleration – when
an object slows down
Calculate Acceleration
A = Velocity2 – Velocity1
Change in Time
NEWTON’S 2ND LAW – F = M X A
• As the mass of an object increases, the
acceleration will decrease
• If you want it to have the same
acceleration, you must increase the
force you apply
• As the force on an object increases, the
acceleration will increase
Calculating Newton’s 2nd Law
FORCES
• Balanced force – does not cause a change in motion
• You could be moving at a constant velocity OR you could me not
moving at all
10 N
10 N
Net Force = 0 Newtons
• Unbalanced Force – causes a change in motion
• Would cause a change in motion like.. Speeding up, slowing down or
changing directions
10 N
15 N
Net Force = 5 Newtons Left
NEWTON’S 1ST LAW - INERTIA
• An object in motion will remain in motion at the same speed and in the
same direction unless acted on by an unbalanced force
• Inertia – the tendency for an object to keep doing what it is doing.
• EX: when you are moving in a car, if the car stops your body is still in
motion and tries to keep moving
• The more mass something has,
the more inertia
If the car stops, the person’s body remains
in motion until the unbalanced force
(seatbelt) stops them
NEWTON’S 3RD LAW
• For every action, there is an equal and opposite reaction
• All forces act in pairs.
Action – the gun pushes
the bullet out
Reaction – the bullet
pushes back on the gun
SIMPLE MACHINES
• Simple Machines do NOT make you do less work
• Work = Force x Distance
• Simple machines make work easier, by increasing the
distance that you apply the input force
GRAVITY
• Earth’s gravity accelerates all objects
towards the center of the earth at 9.8 m/s2.
That means, every second something fall, it
will get 9.8 m/s faster.
• The strength of gravity depends on mass
and distance
• The more mass an object has, the stronger
its gravitational pull
• The bigger distance between objects, the
less gravitational pull
Time
Speed
1 second
10 m/s
2 second
20 m/s
3 seconds 30 m/s