Transcript Slide 8

Slide 1
Fig. 5.1, p.113
Slide 2
Fig. 5.2, p.114
Slide 3
Fig. 5.2d, p.114
Slide 4
Table 5.1, p.118
Newton’s Laws
• Newton’s First Law
– An object moves
with a velocity that
is constant in
magnitude and
direction, unless
acted on by a
nonzero force.
Slide 5
Fnet  F
Fnet  F
Slide 6
Fig. 5.4, p.118
Newton’s Laws
• Newton’s Second Law
– The acceleration of an object is directly
proportional to the net force acting on it and
inversely proportional to its mass.

 F
a
m
Slide 7
Newton’s Laws
• Newton’s Third Law
– If object 1 and object 2 interact, the force
exerted on object 1 by object 2 is equal in
magnitude but opposite in direction to the
force exerted by object 2 on object 1.
Slide 8
Slide 9
Fig. 5.5, p.120
Gravitational Force
• This is the mutual force of attraction on any two
objects in the Universe.
m1m2
Fg  G 2
r
where G = 6.67 x 10-11 Nm2 /kg2
is the Universal Gravitational Constant
• On Earth, this reduces to:
Fg  w  mg
where ‘w’ is the Weight of the object
Slide 10
The Normal Force
• Newton’s Third Law applies to any
two objects interacting with one
another. For an object resting on a
surface, the “pair” of forces are the
Weight of the object and the Normal
force.
Slide 11
Slide 12
Fig. 5.6, p.121
The Tension Force
• The Tension force is caused by a rope,
string, chain, etc. that is attached to
an object.
Slide 13
Slide 14
Fig. 5.7, p.123
Free-body Diagram
• When we are interested in the motion
of an object, we need to be able to
identify all of the forces acting on
that object.
• To do this, we draw a Free-body
Diagram
Slide 15
Slide 16
Fig. 5.8, p.123
Slide 17
Fig. 5.10, p.124
Slide 18
Fig. 5.11, p.126
Slide 19
Fig. 5.12, p.127
Slide 20
Fig. 5.14, p.129
Slide 21
Fig. 5.15, p.130
Friction
• If an object is on a rough surface, it will experience friction,
which opposes the motion of the object.
• If you are trying to push something across a rough surface,
but you are not pushing hard enough to overcome the
friction, then you are experiencing the force of static
friction.
f s  s n
• If you are pushing an object across a rough surface and it is
moving, then you are experiencing the force of kinetic
friction.
f k  k n
Slide 22
Slide 23
Fig. 5.16, p.131
Slide 24
Table 5.2, p.132
Slide 25
Fig. 5.18, p.134
Slide 26
Fig. 5.19, p.134
Slide 27
Fig. 5.21, p.136
Slide 28
Fig. P5.18, p.141
Slide 29
Fig. P5.22, p.142
Slide 30
Fig. P5.26, p.142
Slide 31
Fig. P5.31, p.143
Slide 32
Fig. P5.45, p.145
Slide 33
Fig. P5.46, p.145
Slide 34
Fig. P5.55, p.146
Slide 35
Fig. P5.58, p.146
Slide 36
Fig. P5.68, p.148
Slide 37
Fig. P5.73, p.149