background

32
BACKGROUND

Upload: bisa

Post on 23-Feb-2016

31 views

Category:

Documents


0 download

DESCRIPTION

BACKGROUND. - PowerPoint PPT Presentation

TRANSCRIPT

Page 1: BACKGROUND

BACKGROUND

Page 2: BACKGROUND

This section introduces the topic of the project, notes any information already available, explains why you are interested in the project, and states the purpose of the project.

Background

•Why was this study performed?

•What knowledge already exists about this subject?

•What is the specific purpose of the study?

The BTB LabIn multicellular organisms (humans, for example), specialized organs and systems are used to exchange the gases in respiration with the external environment. The function of the respiratory system is to take oxygen (O2) into the body and to release carbon dioxide (CO2) and water (H2O) from the body. The presence of carbon dioxide can be detected with the testing solution bromthymol blue. A change of color in this solution indicates the presence of carbon dioxide.In this investigation, you will learn how to detect the presence of carbon dioxide with bromthymol blue. You will see that people produce carbon dioxide while breathing. You will also discover the effect that exercise has on the amount of carbon dioxide produced.

Page 4: BACKGROUND

Transformations: Work Lab

Page 5: BACKGROUND

Background• You see two routes to the top of a mountain. One is a road that goes straight up and another is

a path that goes around the mountain. • What takes more work, a shorter route with a steeper incline,

or a longer route with a gradual incline?• Energy is the ability to do work. When work is done,

potential energy can be increased and potential energy is related to an object’s position or height.

• From the field of physics, we also know that work=force*distance.

• Is the force same or different for the level of incline? • In this investigation, you will learn if the force and work used

for different distances are the same or not.

Page 6: BACKGROUND

+ for excellent, perfect, thorough√ for okay, minor mistake- for missing many things or many mistakes

Page 7: BACKGROUND

Research Question/Aim

• To investigate the effect of distance on the force, and ultimately, the amount of work done. In the case of choosing between two routes to the top of a mountain, is there more work done going straight up the mountain or taking the long scenic route around to the top?

Page 8: BACKGROUND

Title/Aim: Do you do more work going straight up a mountain or taking the longer scenic route around to the top?Hypothesis If…..then…..because……

Variables

Procedure

Blank Tables

Page 9: BACKGROUND

Variables

• Independent Variable- Incline/Distance• Dependent Variable-Amount of Work (Force)• Constant/Controlled Variables...-Ramp Set-Newton-meter-Toy Car - Steady speed for how the car is pulled

Page 10: BACKGROUND

How will variables the be changed, measured or controlled?

• The independent variable will be changed by using different distances. (0.5 meters, 0.6 meters… and 1.0 meter are the different distances in the ramp where the car goes up.)

• The amount of work will be measured by calculating the force (Newtons)* the distance (meters). We will measure the force by attaching a Newton-spring to the toy car and pulling it up towards the desired distance.

• The car used in the experiment should be the same because if there are different cars, they could have different mass or ability to roll

• The height of the ramp should be equal too because it can give different results.

• Also, the Newton-meter should be calibrated at 0 Newtons.

Page 11: BACKGROUND

+ for excellent, perfect, thorough√ for okay, minor mistake- for missing many things or many mistakes

Page 12: BACKGROUND

Hypothesis (Qualitative)• If the distance increases, • then all of the amount of force exerted and work

will be less • because even though there is a long distance, the

incline is not as steep and so gravity isn’t pulling as strong on the car.

Page 13: BACKGROUND

Hypothesis (Quantitative)

Work of A (Short Distance) Work of B (Long Distance)Force*Distance (A) Force*Distance (B)10*0.5 3*1.0

5>3

Force(A)>Force(B)

Therefore, the amount of work is more for Route A (straight up) compared to Route B (long way).

Page 14: BACKGROUND

+ for excellent, perfect, thorough√ for okay, minor mistake- for missing many things or many mistakes

Page 15: BACKGROUND

Diagram of Apparatus

Page 16: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes

Page 17: BACKGROUND

Materials

• 1 Ramp• 1 stool• 1 Newton-spring• 1 Toy Car• 6 Distance Markings (0.5-1.0)• 1 meter stick• Roll of tape

Page 18: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes

Page 19: BACKGROUND

Method1) Gather and prepare materials.2) Calibrate Newton-Meter to 0 joules.3) Use a meter stick to measure 0.5 meters on the ramp and mark this with a piece

of tape. Repeat in 0.1 meter increments until all lengths between 0.5 and 1.0 meters are marked (6 total marks).

4) Adjust the ramp so that the 1.0 meter mark is level with the top of the stool. A wedge or someone’s foot may need to be used at the bottom of the ramp to keep it from sliding.

5) Attach Newton-Spring to car by connecting the hook of the Newton-spring with the hole located at the back of the car.

6) Pull the Newton-Meter carefully so that it carries the car up to the distance mark.7) Record the amount of Newtons.8) Repeat Steps 5- 7 for Trial 2 and 3.9) Repeat Steps 5-8 for each of the remaining distances (0.9,0.8,0.7,0.6, and 0.5

meters), making sure to line the marker for each distance with the top of the stool.

Page 20: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes

Page 21: BACKGROUND

Data Table

DistanceD/m

Force of CarTrial 1

Force of CarTrial 2

Force of CarTrial 3

Force of CarAverage

WorkW=F*D

0.5 (A) 4.4 4.3 4.3 4.3 2.2

0.6 3.9 3.8 3.7 3.8 2.3

0.7 3.3 3.5 3.5 3.43 2.4

0.8 3.1 3.1 3.1 3.1 2.5

0.9 2.6 2.6 2.6 2.6 2.3

1.0 (B) 2.4 2.4 2.4 2.4 2.4

N*m or J

Page 22: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes

Page 23: BACKGROUND

Sample Observation Checklist Yes NoIs a direct statement of the results (not an interpretation or an inference)

Note: Imagine the data talking to you. What is it saying?

Ex: The amount of force consistently decreased as the distance increased but overall the work stayed almost the same. The work did not show a consistent pattern as it increased between some distanced, decreased for the other distances, or did not change at all.

Page 24: BACKGROUND

Summary of Observations

• Results show that the work done for Route A and B are different with 0.2 joules of work done more with Route B than A. Work for the other distances are similar with 0.6 meters and 0.9 meters both using 2.3 joules of work done. 0.7 and 0.8 used 2.4 and 2.5 joules, accordingly.

Page 25: BACKGROUND

Conclusion (Aim)In the case of choosing between two routes to the top of a

mountain, the work done going straight up (Route A) the mountain and taking the long scenic route around (route B) to the top:

• it is difficult to tell whether the work is the same or not from the results given by individual groups;

• however, from the combined results, it becomes clearer that both routes take the same amount of work.

• For example, our group results had a difference of 0.1 J between Route A and B, with Route A using 2.2 J of work and Route B using 2.3 J of work. However, the class average results only had a difference of 0.02 between Route A and B, with both routes taking about 2.2 J of work.

Page 26: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes

Page 27: BACKGROUND

Explaining the Science (Work Lab):

• When comparing work done (A:straight up or B: longer), the amount of work done does not change• Even though the force and the distance change, they

cancel each other out.• Shorter distance required more force, W = f x d• Longer distance required less force, W= f x d

Work of A (Short Distance) Work of B (Long Distance)

Force*Distance (A) Force*Distance (B)

10*0.5 5*1.0

5=5Force(A)=Force(B)

Therefore, the amount of work is same for Route A and B.

Page 28: BACKGROUND

So why differences in force?

• Shorter distance=STEEPER slope (almost straight up)• MORE effort (force) directly against gravity

• Longer distance = less steep slope

• LESS effort (force) directly against gravity

Page 29: BACKGROUND

• Also Work = PE = m x g x h.• In the case of this experiment:

• the mass was the same because the same car was used,

• Acceleration due to gravity is a constant so it was the same,

• and height was also the same- the top of the mountain/ramp did not change.

• Therefore, the PE and thus the amount of Work, is the same.

Explaining the Science (Work Lab)

Option 2:

Page 30: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes

Page 31: BACKGROUND

EvaluationWeaknesses/Errors How it affected the

resultsImprovement

The ramp set was too unstable.

The toy car might have done more or less work.

Attach the legs of ramp set to the ground.

The inclines were hard to determine because of

nothing to hold the ramp in place.

The distances of the ramp was not exact.

Have clear ramp so the tape markings can be matched better to the

stool height.

The Newton-Meter was very shaky because of the

toy car.

The amount of Newtons was not exact.

Hold the Newton-Meter in place so that it doesn’t

shake.

Rounded numbers to tenth place

Less accurate Round to the hundredths

These errors might have altered the final outcome slightly, but we could still determine the correct outcome of the experiment. I think that the experiment was still a fair test even though there were some minor mistakes.

Page 32: BACKGROUND

+ for excellent, perfect, thorough√ for good, maybe some minor mistake- for missing many things or many mistakes