Download The Laws of Motion

Created by Mrs. Herman
2012
• Force – a push or pull on an object in a
particular direction (measured in Newtons)
• Push in your chair, pull out a drawer, etc.
• Contact force – a push or pull on one object
by another object that is touching it.
• Pressing keys on computer key board, hitting a
baseball with a bat, etc.
• Noncontact forces – a force that one object
can apply to another object without touching
it
• Gravity, magnetic force, electrical force
Forces can affect motion in several ways:
They can make objects start
moving, move faster, move
slower, stop moving, change
direction, change shape
Since force cause change in the speed or direction of
an object, we can say that forces cause changes in
velocity, so…FORCES CAUSE ACCELERATION!!
• Two or more opposite forces are balanced forces if their effects cancel each
other and they do not cause change in an object’s motion.
• Unbalanced forces is when one force is stronger then the other and cause a
change in motion, speed and /or direction.
• Gravity is an attractive force that exists between all
objects that have mass.
• Mass is the amount of matter in an object (kg)
• Law of Universal Gravitation – all objects are
attracted to each other by a gravitational force. The
strength of the force depends on the mass of each
object and the distance between them.
Lesson 1 resources, review, personal tutor: gravity
• Static Friction – prevents surfaces from sliding
past each other. Up to a limit, the strength of the
static friction changes to match the applied force.
• Sliding friction – sliding friction opposes the
motion of surfaces sliding past each other.
• Fluid friction – friction between a surface and a
fluid such as water or air.
The law says that a thing will keep doing what is doing.
It will only change when something else makes it
change.
According to Newton’s First Law, if
the net force on an object is zero, the
motion of the object does not
change.