Transcript Conservation of Information

Conservation of
Information
-a test of
memory power
Jeniece, Lauren, and Steph
Instructions…
• You will be given
9 minutes to
study all of the
information on
the next 2 slides
• When time is
up…you take the
quiz for 5 mins.
• 1min. to check
your answers
Just some examples
from the Real World…
• Roller coasters
• Pendulums
• A ball in a half pipe
• A free falling object
You now have 6 minutes
…TO CRAM!!!
• work is done: against
• Impulse=force x time
another force or to change
• Total Energy=Kinetic
an obj. speed
Energy +Potential Energy
• running & walking use same
• Kinetic Energy=1/2 mv2
amt. of work
• Potential Energy=mgh
• power is the rate that work
is done
• Work=force x distance
• PE is present in chemical
– work unit=Joules
changes
• Power=work/time
• 2x speed = 4x KE
– power unit=Watts
• 2x distance = 2x force
• 1Joule of work=1Newton
• 4x work = 2x speed
of energy in 1meter
– Energy unit=Newton/meter • Law of Conservation of
Energy= energy can’t be
• KEi + PEi = KEf + PEf
destroyed or created, only
changed to other forms
Here’s how it’s done.
If a 5 kg ball is dropped from 10 m off the ground, what is the velocity at the
bottom of the path?
m= 5 kg
Pei + Kei = Pef + KEf
d= 10 m
5(9.8)(10) + 0 = 0 + ½ (5) v2
g= 9.8 m/s/s
490 = 2.5v2
KE= 0 J
v2 = 196
Pef= 0 J
v= 14
If it takes Tom 2 minutes to climb a stair case 20 m high, and Tom weighs 90
kg, how much work is done and how much power is outputted?
W=mgd
P= W/t
W= ?
W=90(9.8)(20)
P=?
P= 17940
m= 90 kg
W= 17640 J
W= 17640 J
120 s
g= 9.8 m/s/s
t= 2 min. (120 s)
P= 147 W
d= 20 m
Answers to your quiz.
1)
a. –PE = 1440.6 J
b. v = 11.7 m/s
2)
a. PE = 3160.5 J
b. 15.01 m/s
3)
a. W = 735 J
b. P = 4.1 W
4)
a. W = 8467.2 J
b. 11.76 W
5)
a. 13230 J
b. v = 24.24 m/s