It was discovered that a sliver of a special kind of rock would tend to point
North (when set on a leaf in a pool of water or balanced on a pin). This
discovery was worked into creating a compass.
The end of the sliver that pointed North was called the No
Lesson 8 Explosions and Other Problems
Monday, December 09, 2013
2:00 PM
Unit 4 Momentum Page 1
b) Find the change in KE.
Unit 4 Momentum Page 2
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1. Take home quiz
Lesson 6 2-Dimensional Momentum
Monday, December 09, 2013
1:59 PM
Unit 4 Momentum Page 1
The lighter can moves off twice as fast in the opposite
direction.
Unit 4 Momentum Page 2
Unit 4 Momentum Page 3
Unit 4 Momentum Page 4
Unit 4 Momentum Page 5
Unit 4
Lesson 5 1-Dimensional Momentum
Monday, December 09, 2013
1:59 PM
Unit 4 Momentum Page 1
Unit 4 Momentum Page 2
Unit 4 Momentum Page 3
Unit 4 Momentum Page 4
Throw the camera directly opposite to the space
shuttle, and use conservation of momentum
b) find
Physics 12
Name:_
Score: _/12
Momentum Quiz #2
Version 1
Show work clearly, including all substitutions, etc. Make clear diagrams where necessary. Check
your sig figs!
1.
A 1200 kg car is moving East at 30.0 m/s and collides with a 3600 kg truck moving at
Lesson 7 Problems Involving Momentum and
Energy
Monday, December 09, 2013
1:59 PM
Unit 4 Momentum Page 1
Unit 4 Momentum Page 2
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Unit 4 Momentum Page 4
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Unit 4 Momen
Physics 12
Name:
The Ultimate Vector Momentum Assignment
Key Formulae:
p = mv
and
p = F t
REMEMBER, MOMENTUM IS A VECTOR! YOU WILL BE DRAWING TIP-TOTAIL VECTOR DIAGRAMS FOR MOST QUESTIONS, UNLESS NO ANGLES ARE
MENTIONED!
9401
1.
2.
3.
9406
4.
5.
9501
6.
9
Thus we get for the average torque:
taverage = (2/p) N A I B .
But we usually describe motors by their power, not by their torque. Recall
that Power is energy per time, and energy is force through a distance.
For rotations, this becomes: energy is torque
Consider the situation in the figure below:
A current loop (with current direction going
counter-clockwise) is situated in a Magnetic
Field going from North to South poles.
We need to consider the forces on each of the four sides of the current
loop.
The
magnitude: Fmagnetic = q v B sin(qvB)
direction:
right hand rule
magnitude: F = (1.6 x 10-19 Coul) * (3 x 104 m/s) * (.05 T) * sin(90o) = 2.4 x
10-16 Nt.
direction: thumb = hand x fingers
= West x South = UP.
Note: although the force looks small, consider
DB = (mo/4p) I DL sin(qIr) / r2
For the field at the center of a current loop we have the special equation:
Bat center of loop = mo N I / 2R
where N is the number of turns in the wire,
I is the current in each loop, and
R is the radius of the loop.
What i
With the magnetic force only pushing perpendicular to the motion, it would
seem that we could not use this force to increase the speed of particles and
hence generate energy.
However, humans being clever, consider the following slides.
Consider the follow
Since we cannot seem to isolate one magnetic pole like we could electric
charges, the force equation that is similar to Newtons and Coulombs Law
turns out to be not very useful.
We do have a more useful alternative, though. It turns out that charges
exper
Heavier masses will give bigger radii, but we can shrink the radii if they
become too big by using bigger magnetic fields. Note that by measuring
quantities that we can easily measure (charge, radius, Voltage, magnetic
field), we can determine very tiny m
The final result for this loop is:
t = N A I B sin(qIB) sin(qrF) .
In this orientation, qIB = 90o and qrF = 90o .
If the loop does rotate, we see that
qIB remains at 90o (the current still goes up and down, the field still goes to
the right),
but qrF chan
But we also have the right hand rule in the magnetic force equation, and
well need a right hand rule in the field generating equation also.
B = (mo/4p) q v sin(qvr) / r2
direction: right hand rule
thumb = hand x fingers
Point your hand in the direction of