review introduction section 0 lecture 1 slide 1 lecture 17 slide 1 introduction to modern physics...

Review

Introduction Section 0 Lecture 1 Slide 1

Lecture 17 Slide 1

INTRODUCTION TO Modern Physics PHYX 2710

Fall 2004

Physics of Technology—PHYS 1800

Spring 2009

Physics of Technology

PHYS 1800

Lecture 18

Review for Test 2

Review


Lecture 17 Slide 2


Fall 2004


Spring 2009

PHYSICS OF TECHNOLOGY Spring 2009 Assignment Sheet

*Homework Handout

Date Day Lecture Chapter Homework Due Jan 5 6 7 9

M T W F*

Class Admin: Intro.Physics Phenomena Problem solving and math Units, Scalars, Vectors, Speed and Velocity

1 App. B, C 1 2

-

Jan 12 14 16

M W F*

Acceleration Free Falling Objects Projectile Motion

2 3 3

1

Jan 19 21 23

M W F*

Martin Luther King Newton’s Laws Mass and Weight

No Class 4 4

2

Jan 26 28 29 30

M W Th F

Motion with Friction Review Test 1 Circular Motion

4 1-4 1-4 5

3

Feb 2 4 6

M W F*

Planetary Motion and Gravity Energy Harmonic Motion

5 6 6

4

Feb 9 11 13

M W F*

Momentum Impulse and Collisions Rotational Motion

7 7 8

5

Feb 16 17 18 19 20

M Tu W H F*

Presidents Day Angular Momentum (Virtual Monday) Review Test 2 Static Fluids, Pressure

No Class 8 5-8 5-8 9

-

Feb 23 25 27

M W F*

Flotation Fluids in Motion Temperature and Heat

9 9 10

6

Mar 2 4 6

M W F*

First Law of Thermodynamics Heat flow and Greenhouse Effect Climate Change

10 10 -

7

Mar 9-13 M-F Spring Break No Classes Mar 16 18 20

M W F*

Heat Engines Power and Refrigeration Electric Charge

11 11 12

8

Mar 23 25 26 27

M W H F*

Electric Fields and Electric Potential Review Test 3 Electric Circuits

12 13 9-12 13

-

Mar 30 Apr 1 3

M W F

Magnetic Force Review Electromagnets Motors and Generators

14 9-12 14

9

Apr 6 8 10

M W F*

Making Waves Sound Waves E-M Waves, Light and Color

15 15 16

10

Apr 13 15 17

M W F*

Mirrors and Reflections Refraction and Lenses Telescopes and Microscopes

17 17 17

11

Apr 20 22 24

M W F

Review Seeing Atoms The really BIG & the really small

1-17 18 (not on test) 21 (not on test)

No test week 12

May 1 F Final Exam: 09:30-11:20am

Review


Lecture 17 Slide 3


Fall 2004


Spring 2009

Physics of Technology

PHYS 1800

Lecture 8

Circular MotionGravitational Forces

Conservation of EnergyConservation of Momentum

Conservation of Angular Momentum

Introduction and Review

Review


Lecture 17 Slide 4


Fall 2004


Spring 2009

Notes on Test

1. Covers Chapters 5-8 (Chapter 8 only qualitatively)

2. ~8 short answer problems or questions (5 point each)

3. 3 Numerical problems based heavily on the material from the homework and Lab/Demo sessions (20 points each). One problem each from Chapters 5, 6 and 7.

4. You will have a formula sheet just like the one in the handout.

5. Test is Thursday February 19 1:30-2:45 in ESLC 46.

Review


Lecture 17 Slide 5


Fall 2004


Spring 2009

What Do We Need To Measure?

• What is the minimum about things we need to know?

• Where things are—a length, L• When things are there—a time, T

• How thing interact with gravity—a mass, M• How things interact with E&M—a charge, Q

• How thing inter act with weak nuclear force• How things interact with strong nuclear force

Review


Lecture 17 Slide 6


Fall 2004


Spring 2009

Describing Motion and Interactions

Position—where you are in space (L or meter)

Velocity—how fast position is changing with time (LT-1 or m/s)

Acceleration—how fast velocity is changing with time (LT-2 or m/s2)

Force— what is required to change to motion of a body (MLT-2 or kg-m/s2 or N)

Energy—the potential for an object to do work. (ML2T-2 or kg m2/s2 or N-m or J)

Work is equal to the force applied times the distance moved. W = F dKinetic Energy is the energy associated with an object’s motion. KE=½ mv2

Potenital Energy is the energy associated with an objects position.Gravitational potential energy PEgravity=mghSpring potential energy PEapring= -kx

In this chapter we will develop the concept of…MOMENTUM…and and its associated law of Conservation of Momentum and apply this to collisions.

Review


Lecture 17 Slide 7


Fall 2004


Spring 2009

Newton’s Laws in Review

• 1st Law —a special case of the 2nd Law for statics, with a=0 or Fnet=0 • An objects velocity remains unchanged, unless

a force acts on the object.

• 2nd Law (and 1st Law)—How motion of a object is effected by a force.– The acceleration of an object is directly

proportional to the magnitude of the imposed force and inversely proportional to the mass of the object. The acceleration is the same direction as that of the imposed force.

• 3rd Law —Forces come from interactions with other objects.• For every action (force), there is an equal but

opposite reaction (force).

F ma

units : 1 newton = 1 N = 1 kgm s2

Review


Lecture 17 Slide 8


Fall 2004


Spring 2009

Central Forces and Gravity

Review


Lecture 17 Slide 9


Fall 2004


Spring 2009

The Math Approach

• We are going to explore a different kind of central force that is no longer constant, but is proportional to 1/r2.

20

0

2

1

222attvt

vvt

vvd

t

vvaoratvv

ga

ofoo

off

k/r2

We will take a pragmatic approach (hindsight is 20-20!)

We simply replace the force of the “string” with the force of gravity

2rkT gravitystring F

Review


Lecture 17 Slide 10


Fall 2004


Spring 2009

Newton’s Law of Universal Gravitation

• Newton recognized the similarity between the motion of a projectile on Earth and the orbit of the moon.

• If a projectile is fired with enough velocity, it could fall towards Earth but never reach the surface.

• The projectile would be in orbit.

• Newton’s law of universal gravitation says the gravitational force between two objects is proportional to the mass of each object, and inversely proportional to the square of the distance between the two objects.

• G is the Universal gravitational constant G.

221

r

mGmFgravity

Review


Lecture 17 Slide 11


Fall 2004


Spring 2009

Energy

Review


Lecture 17 Slide 12


Fall 2004


Spring 2009

• The mechanical advantage of a simple machine is the ratio of the output force to the input force.– For the pulley example, the mechanical advantage is 2.

• Work is equal to the force applied times the distance moved.– Work = Force x Distance: W = F d

– Work output = Work input• units: 1 joule (J) = 1 Nm= 1 kg m2 / s2 [ML2T-2]

Mechanical Advantage and Simple Machines

Review


Lecture 17 Slide 13


Fall 2004


Spring 2009

Energy: The potential to do work.Conservation of Energy: The total

energy of a closed system remains constant.

– Energy can be converted from one form to another.

– Not all forms of energy can be fully recovered.

Conservation of Energy

Time

Ene

rgy

Review


Lecture 17 Slide 14


Fall 2004


Spring 2009

The horizontal position x of the mass on the spring is plotted against time as the mass moves back and forth.

• The period T is the time taken for one complete cycle.

• The frequency f is the number of cycles per unit time. F=1/T

• The amplitude is the maximum distance from equilibrium.

X(t) = A sin (2π f t)

Review


Lecture 17 Slide 15


Fall 2004


Spring 2009

Impulse-Momentum Principles

Review


Lecture 17 Slide 16


Fall 2004


Spring 2009

Momentum and Impulse• Multiply both sides of Newton’s second law by the time interval over which the force acts:

• The left side of the equation is impulse, the (average) force acting on an object multiplied by the time interval over which the force acts.

• How a force changes the motion of an object depends on both the size of the force and how long the force acts.

• The right side of the equation is the change in the momentum of the object.

• The momentum of the object is the mass of the object times its velocity.

vF

vaF

mt

tmm

net

net

p mv

Review


Lecture 17 Slide 17


Fall 2004


Spring 2009

Impulse-Momentum Principle

The impulse acting on an object produces a change in momentum of the object that is equal in both

magnitude and direction to the impulse.

impulse = change in momentum

= p

In analogy,

work = change in energy= ΔE

Review


Lecture 17 Slide 18


Fall 2004


Spring 2009

Rotational Motion and Forces

Review


Lecture 17 Slide 19


Fall 2004


Spring 2009

Formulas We Know and Love

review introduction section 0 lecture 1 slide 1 lecture 17 slide 1 introduction to modern physics...

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