physics -forces cp9 p2 Flashcards
what is a contact force
-forces which have to be in
contact or touching the
object to apply the force.
-These are either a PUSH
or PULL
different types of contact forces
-Thrust : Makes an object
move
-Air resistance : tries to
slow down a moving object
-Water resistance : tries to
slow down a moving
object in water
-Drag : Any force which
tries to stop an object
moving
-Normal Contact force:
Force at 90o
to a surface, eg the
ground holding us up
what is a non-contact force
These are forces which can act on an object without touching them
examples of non-contact forces
-Gravity : This makes
everything fall, on Earth it
makes things accelerate at
10m/s2
-Electrostatic : Charged
objects will exert a force
on each other and neutral
objects
-Magnetic : Magnets will
exert a force on each other or magnetic metals such as IRON, COBALT, STEEL and NICKEL
force interaction on objects explained
When a chair is on the floor there are 2 equal and opposite forces.
The chair exerts a force on the ground, the ground exerts an equal
and opposite force on the chair.
forces are scalar or vectors
vectors - have magnitude and direction.
what is a resultant force
-This is the force left, which
makes an object
accelerate after we
have added or subtracted
all other forces
-Forces in opposite
directions SUBTRACT
Forces in the same
direction ADD
what is equilibrium
This is when the forces on an object in
different directions cancel. The resultant
force is ZERO.
what is moment
-This is the turning effect of
a force perpendicular
distance
-A moment can make
something rotate
clockwise or anticlockwise
levers
-These allow you to
increase the distance of
the force from the pivot.
-Adv—A smaller force is
required
-Dis—You have to move
the force further
gears
-If you turn one gear it
makes the next gear move
in the opposite direction
-If the gears are the same
size they turn at equal
speeds.
