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Position, Velocity, and Acceleration
Announcements
Understand all material in assigned chapters whether in lecture or not. Read Ch 1-2 for next week.
HW 1 is due 1 AM this morning.
Help sessions begin next week – across from 113
One 3x5 index card is allowed for any quiz or test.
Expect unit conversion and scientific notation problems. NO CALCULATORS allowed on first quiz.
HW 2 has some units and sci. notation problems on it.
HW Software
The science that studies matter, energy, force, space, time, and the interactions between them.
Basic Formulae – Clicker Q #1Physicists simplify the universe into planes, cubes,
circles, lines, cylinders, and particularly – spheres! You are assumed to know the length, area and volume formulae from geometry
A sphere has radius R, it's surface area and A sphere has radius R, it's surface area and volume are, respectively:volume are, respectively:
A) R2 & 4 R
B) 2 R & 4 R2
C) 4 R2 & 8 R3
D) 4 R2 & (4/3) R3
E) (4/3) R3 & 4 R4
Average vs. instantaneous velocity
How do you get the slope of a curve?
Getting velocity from position vs. time graphs
Getting acceleration from velocity vs. time graphs
Relation between position, velocity, and acceleration
Obtaining v and a from graphs(clicker #2 and #3)
v from x vs. t (clicker #4)
a from v vs. t (clicker #5)
x vs. t – not y vs. x
INSTS = vr
Instantaneous Speed
Instantaneous speed is
Magnitude of instantaneous velocity
AV
∆∆x
v =t
Average Velocity
Total displacement (delta-x) in delta-t divided by delta-t
Instantaneous Velocity
Instantaneous velocity (or just “velocity”) is displacement dx in infinitesimal time dt divided by dt.
d
d
xv =
t
0 0lim lim AVt t∆� ∆�
∆ =∆x
v = vt
Displacement
Position
∆x
x Coordinate of object at time t.Difference in coordinate between time t and later time ∆t + t
1-Dimensional motion definitions
Position, velocity, and acceleration
Velocity dxv =
dt
Position x
Acceleration dva =
dt2
2
d xa =
dt
m
ms
2ms
Equations for the week