Work = Fd

•Work (Joules) = Force (Newtons) X Distance (meters)

•1. Force = 5 Newtons, Distance = 8 meters, Work = ____ Joules?

•2. Force = 10 N, Distance = 10 m, Work = ___ J?

•3. Distance = 15 m, Force = 20 N, Work = ___ J?

•4. Work = 30 J, Distance = 6 m, Force = ___ N?

•5. Work = 55 J, Force = 5 N, Distance = ___ m?

•

Lab #3 – Calculating Work

Lab #3 – Calculating Work

Work = Force x distance

Work = (Force)(Distance)

W = Fd

Problem

How can a ramp help us pull a heavy object up to a greater height?

Hypothesis

Materials

Ruler, chair, ramp (inclined plane), weights, spring scale, various metallic objects

   

Procedure

Results

A.Work done without ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight	__N	__cm	___J
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

  

B. Work done with ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight	N	cm	J
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

  

Make another Hypothesis: Use your hands to feel the wool blanket and the plastic maps.  Which of these will cause more work to be done on the weights? 

C.Work done with plastic map and ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

D.Work done with wool blanket and ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

  

ANALYSIS

1)   Make two graphs to compare your Results: Graph 1 will compare the data in A and B, Graph 2 will compare the data in B, C, and D.

2)   How did the weight (force pulling down) affect the amount of work done on the object?

3)   Compare/Contrast the trial with the least amount of work to that with the most amount of work.

4)   Part 1 (A,B): What is your Independent Variable?

5)   Part 1 (A,B): What is your Dependent Variable?

6)   Part 1 (A,B): What are your Constants?

7)   Part 2 (B,C,D): What is your Independent Variable?

8)   Part 2 (B,C,D): What is your Dependent Variable?

9)   Part 2 (B,C,D): What are you Constants?

10)               Ponder and Discuss: What are two surfaces that would increase the force needed to pull the weights up the inclined plane?  What are two surfaces that would make work easier?

Conclusion

What was your problem?

Restate your hypothesis.  Was it right? wrong?  why or why not?

What did you learn in this lab?

What did you like about this lab?

What were some challenges you had to deal with?

What could you do next with this problem?  What other tests could you perform?

Write down any other additional thoughts, observations, inferences, etc.

Friction is a force that opposes motion

Brainpop video and quiz: http://www.brainpop.com/science/motionsforcesandtime/force/

The friction song!

Mythbusters phonebook fiction!!!

Friction & Gravity: Forces at Work

HW - 11/12/13

   11/12/13

•HW

C3S1 pp. 74-76, RC, BQ, Applying Math #1-2, SC#1

11/21/13
C3S1 p. 78 - Read Work and Energy
C3S2 p. 84 - Read Friction and Friction and Efficiency, Physical Setting Q/A

11/25/13

C3S2, RC, BQ, self check #1; Find 3 examples of a machine making work easier.

Energy transforms...

Energy transforms...

from www.dictionary.com:

energy  (ěn'ər-jē) Pronunciation Key
The capacity or power to do work, such as the capacity to movean object (of a given mass) by the application of force. Energycan exist in a variety of forms, such as electrical, mechanical,chemical, thermal, or nuclear, and can be transformed from oneform to another. It is measured by the amount of work done,usually in joules or watts.

 A. Types of Energy:

     1) Potential Energy is the energy of position.  An object's mass andheight give an object its potential energy.  The greater the mass or the higher an object is, the more P.E. an object has.

  Potential Energy = (mass)(gravity)(height) or P.E. = mgh

     2) Kinetic Energy is the energy of movement, motion.   An object's massand speed/velocity determine its kinetic energy.  The greater the mass and the more speed an object has, the more K.E. an object has. 

Kinetic Energy = 1/2(mass)(velocity)(velocity) or K.E. = 1/2 mv²     

B. Forms of Energy

Energy can come in a variety of forms.

1. Atomic/Nuclear Energy is produced when you split atoms. 

Examples:Atomic bombs, nuclear power plants, and the sun.

2. Chemical Energy - is really a form of potential energy and is the energy stored in food, gasoline or chemical bonds.
Examples: Striking a match, food, batteries.  

3.  Electrical Energy - Energy produced by electrons moving through a substance is known as electrical energy. We see evidence of electricity in household appliances, electric outlets, phone chargers, electric wires.
Examples: MP3 players, computers, video games, holiday light wires.

4. Mechanical Energy - is the energy of movement. All moving objects have mechanical energy. Examples: bicycles, machine parts, subway trains, wheels, us!

M.E. = P.E. + K.E.

  

5. Sound Energy- is produced when a solid, liquid or gas vibrates. Sound energy travels out as waves in all directions.
Examples: Voices, sirens, horns and musical instruments.

 6. Radiant Energy - is light energy, that when absorbed by an object, gets converted to thermal/heat energy. 

 Examples: A light bulb, the glowing coils on a toaster, the sun, and even headlights on cars. 

7. Thermal Energy - is the energy of molecular movement.  The faster the molecules move, the more thermal energy is present.  Heat is the transfer of thermal energy i.e. when thermal energy moves from object to object, we feel it as heat.

C. Generating Electricity!!!

- Electrical energy is needed in our daily lives.  Imagine what life would be like if all those appliances that you plug in on a daily basis were to disappear...   No refrigerators, no MP3s, no television, no hot water, etc.

Power plants use a generator to generate electricity.  A turbine turns the generator.  Mechanical energy is needed to turn the turbine, usually in the form of steam pushing against its blades.  Now, all we need is a source of thermal energy to boil the water into a gas.