10. forces and motion Flashcards
(26 cards)
main forces
tension- acts away from particle
thrust- acts towards particle
weight- mass of particle g is acceleration due to gravity (9.8m/s^2)
friction-acts parallel to surface in the opposite direction to motion
normal reaction-acts perpendicular to the surface
weight formula
W= mg
newtons first law of motion
object at rest or object moving with constant velocity will continue to move with constant velocity unless a force acts on the object
resultant force is
the sum of forces acting on a particle
unbalanced force is a
force acting on a particle that is not cancelled by another force acting in the opposite direction
directions of two dimensions are usually
horizontal and vertical or parallel and perpendicular to an inclined plane
vectors have
magnitude and direction
force is measured in
direction of force is an angle measured
newtons
degrees
newtons second law of motion
resultant force acting on a body is equal to the product of mass of body and its acceleration
F=ma
F=ma units
F= newtons
m= kg
a=m/s^2
newtons third law of motions
two bodies the force exerted on the second by the first is equal in magnitude but opposite in direction to the force entered on the first body by the second
connected particles refer to
situations where two bodies are connected in some way
rope would be modeled as
light inextensible string
light-small mass that its ignored
inextensible- cannot be extended/shortened in length
string would only be in …..
tension
tow bars is a
mechanism by which a car can be connected to a caravan, trailer
tow bars how are they modeled
light inextensible rod
a rod can either be in
tension or thrust
coupling is
a general term referring to the connection between two objects
pulley allows a inextensible string to change its
orientation
pulleys will always be
smooth and light ,, no friction involved and mass is negligible
peg is a
fixed point that a particle can be suspended from
vector quantities + unit
displacement m
velocity m/s
acceleration m/s^2
force/weight N
scalar quantities
distance m
speed m/s
time s
mass kg
scalar quantities have
only magnitude
