Transcript Forces from Motion

Forces from Motion
Chapter N3
Key Ideas…
The Kinematic Chain
d
d
r (t )  v (t )  v (t )  a (t )
dt
dt
Net-Force Diagrams
Draw FBD
Express forces in vector form
Combine
Net force implies acceleration
Practice Questions…
 Graph shows
motion of two trains
on parallel tracks
and who beside
each other at time t
= 0 s. Describe
their motion.
 Do the trains ever
have the same
speed? If so
when?
 Do the trains ever
have the same
acceleration?
Practice Questions…
 A car rounds the top of a circular
hill at a constant speed.
 Draw a force diagram and identify all
forces
 Draw the net-force
 How will the force diagram change
as the speed changes?
 Is it possible for the normal force to
be zero? What would “zero normal
force” mean?
 Is there a maximum speed for which
the car can drive over this hill and
still remain in contact with the road?
From Moore…
N3B.1
N3B.9
N3S.7
N3R.2