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History Earliest application was to the heavens:

geocentric vs. heliocentric models of the solar system

2.1 Displacement Distance vs. Displacement Scalars and Vectors

Δx = xf - xixi

xf

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2.2 Average Velocity Speed is a scalar quantity Average speed = distance/time Instantaneous speed and your

speedometer

Velocity is a vector quantity Average velocity = displacement/time

if

if

ttxx

ΔtΔxv

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2.3 Instantaneous Velocity Instantaneous speed and your

speedometer

txv

t

0

lim

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2.4 Acceleration A vector quantity The change in the velocity over time

Name three ways you can accelerate while driving your car?

if

if

ttvv

ΔtΔva

ΔtΔvlima

0Δt

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2.4 Acceleration Explain the car’s motion in each case.

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In class: Question 5 and Problem 3, 16 Other problems ↓

6. The average velocity is given by

8.5cm 3.4 cm 5.1cm

0.78cm s4.5s 2.0s 6.5s

xv

t

The average speed cannot be calculated. To calculate the average speed, we would need to know the actual distance traveled, and it is not given.

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8 laps 0.25 mi lap

2.0 mi 2 mi 1610 m 1 min4.3m s

12.5 min 12.5 min 1 mi 60 sdt

0 m sv x t

9. The distance traveled is 2.0 miles The displacement is 0 because the ending point

is the same asthe starting point.

(a) Average speed =

(b) Average velocity =