Up, Up and Away

download report

Transcript Up, Up and Away

Up, Up and Away
January 25, 2006
Calendar
Today
– Some problems on vectors
– Introduction to some 2D issues
Friday, Monday
– 2D Kinematics
Wednesday
– Exam #1 – Through 2D Stuff finished on Monday
Friday
– Going around in circles
Find the horizontal and vertical components of the d = 140 m
displacement of a superhero who flies from the top of a tall
building following the path shown in the Figure where = 30.0°.
Superperson
The helicopter view in Figure
P3.35 shows two people
pulling on a stubborn mule.
Let the magnitude of F2 =
64.0 N and the angle at
which F1 pulls be =
65.0°.
(a) Find the single force that is
equivalent to the two
forces shown. The forces
are measured in units of
newtons (symbolized N).
(b) (b) Find the force that a
third person would have to
exert on the mule to make
the resultant force equal to
zero.
(c) Use I,j notation
2 Dimensional Motion


We will consider motion the the x-y plane.
Positions now have (x,y) coordinates so we
need to use vectors.


That’s why we did that pointy stuff on Monday
There are two types of problems we need to
consider


Throw or drop an object at an angle to the
horizontal
Make something go around in a circle
Positions are VECTOR quantities
ri  r  r f
ri  r f  r
Velocities
Which way is the acceleration?
In 2D motion, lots of things happen at once!
Velocity
Position
An Example …
What is its velocity here?
It’s acceleration?
How long did it take to get here?
here?
height (h)
RANGE (R)
Let’s Just Do it!
The Monkey Problem – Hit or Miss?
Angle??