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Phys141 – Mon 9/11
Today:
• Rest of Chapter 3: Vectors
• Chapter 4.1: Two dimensional motion
For Wed:
• Read Chapters 4.4 and 4.5 (you can skip 4.6)
• Online Quiz
• Prepare the pre-lab 1-2 paragraph writeup
that has to be handed in prior to lab.
Note on Lab: Normal distribution
Example: Spheres randomly going left or right
as they fall down. After about 10 left-right
decisions, on average the sphere will be in
the center, but it may also be a bit to the
left or to the right.
Now, if 100 spheres are dropped, we can
predict how many will end up straight down,
and how many will end up one right, two
right, one left etc.
Statistics: Can predict what happens on average, and what
the probabilities are for a single sphere, even though we
can’t predict what exactly a single sphere will do!
Vertical direction: y
Gravitational acceleration: g= 9.8 m/s2
Objects starts at position yiwith velocity vi
At time t, it is at positon y(t)
Equation for falling object
2
1
() 2
ii
yt y vt gt=+ +
Chapter 2
