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Sheldon from the Big Bang explains physics

Why is Science Important?
from Alom Shaha on Vimeo.

"The most incomprehensible thing about the world is that
it is comprehensible."

- Einstein

 

 

 



Unit I - Mechanics - Study of the relationship between force and motion

 

I. Kinematics - Mathematical methods of describing and predicting motion

 

Describe motion by using:

A) Average Speed

 

 

Average Speed
of 120 miles per hour

can also be written ...

 

 

 

120 miles/hr

per = divided by

 

Could mean travelled

120 miles in one hour

 

OR ....

 

 

60 miles in ...

 

1/2 hour (30 minutes)

 

 

 

 

30 miles in ...

 

 

15 minutes

 

 

 

 

 

OR 15 miles

 

 

 in 7.5 minutes

 

 

 

 

Can you believe the speed limit in
Calgary, Canada is 100
!!

 

 

 

 

100 km/hr 60 mph

 

 

Avg. Speed - how much distance an object covers per unit time


1)
Units: m/s, km/hour,

          miles/hour

 

Average Speed = Δd/Δt

 

 

 

Distance

 

(meter ≈ 1 yard) 

(km ≈ .6 miles) 

 

 

Time
 - secs, minutes, hours

 

 

 

 

Ex 1) An object travels 5 meters in 2 seconds.

 

Find its speed.

 

Speed = Δd/Δt

 

 

= 5m/2 sec

 

 

 

= 2.5 m/s

 

 

 

 

 

 

Ex 2) An object moves at a rate of 3 m/s for 1.5 seconds.

 

How far did the object move?

 

 

Speed =Δd/Δt

 

3 m/s = Δd/1.5 sec 

 

 

Δd = 4.5 m 

 

 

 

 

Motion Map

 

3 m/s for 1.5 seconds

 

 

 

 

 

 

Δd = 4.5 m

 

Photos made by Eadweard Muybridge (1830- 1904)
Animation by User Waugsberg

Public Domain

 

Ex 3) An object moves at rate of 4 m/s over a distance of 10 meters.

 

How long did it take to travel that distance? t = ?

 

Speed = d/t

 

 

4 m/s = 10 m/t

 

 

(Cross Multiply)

 

 

(4 m/s)t = 10 m

 

(Divide by 4)

 

t = 2.5 seconds

 

 

 

 

 

Motion Map

How much time to travel 10 m @ 4 m/s?

 

 

 

 

 

 

t = 2.5 seconds

 

 

 

 

Motion Plots I

 

 

 

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