Example: In your dorm you have devised a water-balloon launcher that you have placed on a
second-floor window sill that is directly above an exit door and sidewalk. The launcher is 25 ft.
above the ground, is tilted at an angle of 50 deg wrt the horizonta
Newtons Third Law
Example
Block B
Block A
Two blocks on a frictionless surface with two forces acting on the pair .
With no friction, we know the blocks will slide to the right. (Why?)
NOTE: As the blocks slide along the horizontal surface they remain in
Relative Velocity Example: Running Up the Down
Escalator
The longest escalator in the western hemisphere is located in the
Wheaton station of the Washington, DC MetroRail system.
The overall length is
about equal to the
height of the
Washington Monument.
Which of our kinematic equations are most useful for this problem?
So, if the final velocities of the two cars are not the same, what will be the
same for the two vehicles after the police car catches the speeder?
Their final positions must be the same!
S
Ch. 3 Kinematics in Two Dimension (2-D)
Now lets consider the concepts of displacement, velocity, and acceleration in
2 dimensions.
1-D
2-D
x x f xo
x x f
v
t
v v f
a
t
xo
t
vo
t
x f xo vot 1 at 2
2
x
2
v 2 vo
f
2a
r rf ro
r r
r
v
f o
t
t
v
Ch. 2 Kinematics in 1-D
Mechanics
Kinematics
Concepts needed to describe
motion without forces
Chs. 2 and 3
Dynamics
Deals with the effects that forces
have on motion
Ch. 4
Our goal is to describe the motion of some object.
To do this, we must be able to
PHYS 2001 General Physics I
The Nature of Physics
From the very big to the very small, Physics covers it all!
This semester we will focus on
Classical (or Newtonian) Mechanics big things
moving slowly (with respect to the speed of light).
Isaac Newton
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