forces a force is a push or a pull on an object. every force has strength, magnitude and direction....
TRANSCRIPT
FORCES
A force is a push or a pull on an object.
Every force has strength, magnitude and
direction.
Forces acting on a stationary object can set
the object in motion.
They can also change the object’s speed or
the direction it is moving in.
Forces can also change the shape of a
stationary object.
GRAV
ITY Why do things fall to the
ground?Gravity is the force of attraction
between all objects that have
mass.The strength of gravity
between two objects depends
on two things: the mass of the
objects and the distance
between them.
Ele
ctri
c and
Magneti
c Fo
rces
These forces are closely
related.Both are cause by negative and positive
charges in matter.Electric forces are associated with unmoving charges.
Magnetic forces are created by moving electric chages.
Fric
tion
-Friction is the force that opposes
motion between two surfaces that
are in contact with each other.
-Friction might prevent motion
from starting, or it might oppose
motion in progress.-Types of friction include sliding,
rolling, static and fluid.
Bala
nce
d a
nd
Unbala
nce
d F
orc
es
-More than one force can – and
usually does- act on an object at
the same time.-Sometimes these forces are
applied in the same direction.
-Sometimes the forces are applied
in different directions.-The net force on an object is the
combination of all the forces
acting on it.-Force is measured in newtons.
-Force is shown with arrows.
Bala
nce
d F
orc
es
-When the net force is zero, the
forces are said to be balanced.
Balanced forces produce no
change in the motion of an object.
-An object that is not moving will
stay motionless, while an object
that is moving will maintain its
speed and direction. Balanced
forces can, however, crush an
object.
Unbala
nce
d
Forc
es
-When the net force on an object is
greater than zero, the forces are
said to be unbalanced.
Unbalanced forces produce a
change in the motion of an object.
- A motionless object will begin to
move, while an object already
moving will change its speed
and/or direction.
Calc
ula
ting
Net
Forc
e-To find the net force of forces that
are acting in the same direction,
simply add them together.
-to find the net force of forces that
are acting in opposite directions,
simply subtract the smaller force
from the larger one.