Download Physics 11 exam outline

Physics 11 Exam outline 2011




½ MULTIPLE CHOICE ~ 40-50 Questions
½ LONG ANSWER ~ 10-12 Questions
Formula sheet provided
Bring your own Calculator (Note: Calculators with cameras, picture storage,
phones or internet access are not permitted)
Kinematics
 Position time graphs
o Slope = velocity
 Velocity Time Graphs
o Slope = acceleration
o Area beneath graph = displacement
 Variables - symbols
o Velocity, speed, (average vs instantaneous)
o Position, time
o acceleration
 Units
 Unit Conversions
 Significant figures
 Word Problems- DiVersa method
 Vectors /Scalars
 Freefall problems
o Acceleration = g on earth = 9.8 m/s2
Dynamics
 Newton’s 3 Laws
o Inertia
o F=ma
o F2 on 1 = - F1 on 2
 Word Problems- Versa method
 Friction
 Constant Net Force provides Constant acceleration
 Constant velocity means Net force =0
 Mass vs weight
 Real weight vs apparent weight
 Atwood machine – pulley with a mass on either side suspended by a string
over the pulley a = (m1-m2)g/(m1+m2) m1>m2
 Fletcher’s Trolley - cart on a table attached to a mass with a string . The
mass hangs over a pulley over the edge of a table
o No friction: a = m1g/(m1+m2)
o With friction: a = m1g – (mu)(m2g)/(m1+m2)
 Tension – equal throughout length of massless string.
o String must support the weight of everything below it.
 Free body Diagrams
Momentum And Impulse
 J = delta p
 J = F*t
 p = m*v
 F*t = m(delta v)
 Think car crashes and making them safer.
 Think catching with soft vs hard hands
 Conservation of momentum
o The TOTAL momentum of a system (1 or more objects) is
constant unless an external force acts on the system ( providing
an impulse to change the momentum)
o For collisions and recoil (explosion) problems
Work Energy Power
Work (W)
Work is the transfer, or transformation of energy. W = E
Work is defined as a force causing and acting through a displacement and is found
by multiplying the two quantities. W = F d. Since the force in this equation is the
one that causes the displacement, they (F and d) must be completely parallel or at
least have a parallel component. If F and d are at an angle to one another W = F
dcosθ. The angle here is the lesser angle between F and d.
Work has units of newtons times metres or Nm. This combination of units has a
name itself : 1Nx1m = 1joule or j for short.
There are cases when forces or displacements are present yet no work is done.
1. F=0, d ≠0
2. F≠0, d=0
3. F is perpendicular to d
Energy (E)
Energy is defined as the ability to do work. If something can apply a force to
another object (resulting in a displacement of that object) then that something has
“energy”.
The main categories of energy are mechanical, thermal, electromagnetic, and
nuclear. All energies can be grouped into one of these categories.
There are 2 main types of energy: kinetic and potential. Kinetic energy depends on
the speed of an object (a hammer has kinetic energy as it speeds towards the head
of a nail). Potential energy depends on the position of an object ( a rock held 2 m
above a tent stake is in a position to drive a tent stake into the ground... if allowed).
Kinetic energy (Ek)
E k  12 mv 2 where m is the mass in kg and v is the speed in
m/s. This combination of units also gives us joules. (check it out!)
Gravitational Potential Energy (Eg) Eg = mgh where m is mass in kg, g = 9.8 m/s2,
and h is height or vertical position.

W  Fd
 
W  mad
derivation:
so
if the displacement is vertical then the vertical positions d1 and d2 can be renamed
h1 and h2 and the vertical acceleration is 9.8 m/s2 or “g”.
W  mgh
W  mgh2  mgh1
Work produces a change in the vertical position of an object.
Springs - Elastic Potential Energy and Hookes Law
Power (P)
Power is the rate of work and it is also the rate of energy transfer.
P
W
E
where W is work in joules and t is time interval in seconds. also P 
t
t
Power has units of watts. 1 watt = 1 joule/1 second 746 watts = 1 horsepower
Conservation of energy
For a closed system the total of all the energy is conserved (doesn’t change). The
total energy is the sum of all the individual energies. A closed system is one in
which nothing enters or leaves.
This can be used just like the conservation of momentum.
It is useful for comparing changes in position with changes in speed.
The conservation of energy in formulas looks like this:
E  E
i
or
f
 E   E  (using prime notation)
Expanded form with prime notation looks like this:



E k  E g  Ee  E k  E g  Ee
If there are no springs present then we can drop the Ee terms giving us:


Ek  E g  Ek  E g
Which can be expanded further to:
1
2

mv 2  mgh  12 mv 2  mgh
Mass is a common factor so it can be removed by dividing through by m.
1
2

v 2  gh  12 v 2  gh
Multiplying through by 2 to simplify:

v 2  2 gh  v 2  2 gh
This is a very useful result giving us the change in speed that corresponds to a
change in height.
If we consider sledding on a hill onto a frozen lake, we know that even though we
may skid a great distance across the ice, eventually we will stop due to friction.
Friction is always acting when surfaces are in contact and converts kinetic energy
into heat.
For a closed system then, any change in energy is due to Work. If work is done to a
system then the energy of the system increases. If the system does work to the
surroundings, then the system loses energy. In other words:
W  E
Waves
 Transverse vs longitudinal
 Frequency, period, wavelength, amplitude, speed
 Universal wave speed equation
 Wave diagrams
o Pulses on a spring
o Wavefront
o ray
 Superposition
o Constructive interference
o deconstructive interference
 Reflection
o θi = θr Law of reflection in 2 and 3d
o From a fixed end (inversion) 1d
o From a free end (no inversion) 1d
 Diffraction
o Bending of waves around obstacles or through openings
o Occurs when wavelength is ~ the same size as the obstacle or opening
 Interference of light and sound and water waves
o In 2d – interference and demoivre patterns
 Constructive interference maxima d1-d2=nλ
 Deconstructive interference minima d1-d2= (2n-1) λ/2
 Characteristics of sound
o Speed and dependence on temp AND MEDIUM
o Frequency determines pitch
o Amplitude determines loudness
o Wavelength depends on medium
o Doppler Shift

Light
o
o
o
o
Speed = c = 3 x 108m/s
Electromagnetic spectrum
Index of refraction
Refraction and Snell’s Law