1-5 Magnification factor (1.2)

• Natuurkunde
• Middelbare school
• havo
• Leerjaar 2

Magnification factor (p. 25)

Bluetooth 

- On

Stationary

- Books

- Pen and pencil

- Calculator

- iPad

Report

- YES book controll

Lessonup

- Yes

Bags in

the cuboard

Phones in the phone holder

Lesson goals:

• At the end of this lesson you should be able to make calculations with the magnification factor. 
• At the end of this lesson, you must be able to write a scienctific report. 

Note: During the next lesson, you will do an experiment, and write a report

Magnification factor

The factor by which the shadow is larger than the object, depends on the distance between the lamp and the object, and the distance between the lamp and the screen. 

If the screen is twice as far from the lamp as from the object, the magnification factor is 2. 

6 m

3 m

... and if the magnification factor is two, the shadow will be twice as large.

3 m

6 m

24 cm

48 cm

Magnification factor formula  

length of shadow= N x length of object

N = magnification factor

Length of shadow

Length of object

N=​V​​B​​

Magnification factor formula

distance of shadow = N x distance of object

N =  magnification factor

distance of object

distance of shadow

N=​v​​b​​

What is the distance of the shadow?

1. 10 cm
2. 30 cm
3. 40 cm
4. 70 cm

Which formula is wrong?

1. length shadow= N/length object
2. N = length shadow/ length object
3. N = distance shadow/ distance object
4. length shadow = N x length object

Steps to do the sums:

Step 1: Write what you are given. 

Step 2: Write what you are asked.

Step 3: Write down the formula, with that which you 

                 want to calculate to the left of the = sign

Step 4: Substitute into the formula

Step 5: Solve the unknown value

Example 1

During a shadow theatre a lamp is at a distance of 180 cm from the screen. A doll that is 16 cm tall, stands between the lamp and the screen at a distance of 60 cm from the lamp. Calculate the hight of the shadow

Calculation:

N = distance shadow/ distance object

     = 180/60 

     = 3 

 shadow = 16 x 3 

                     = 48 cm

Question 29 (p. 27)

Do the following questions:

25, 28, 30, 31 (p. 27)

In your writingbook

Rules: 

- 10 minutes

- No talking

Finished early: also do 24, 26, 27

How to write a scientific report

Start with a titel
Names of group members (and surnames), class, date, name of teacher

1. Introduction
2. Theory
3. Method of measurements
4. Results of measurements
5. Calculations
6. Conclusion and recommendations.

General remarks

• You may not make spelling errors.
• Do the chapters seperatly, and use bold, cursive, underline and colours to clear things up. 
• Formulas must be written in their own line, and get a number. 
• Dont write in the we/ I form
• Number the figures, graphs and photo's. 
• Write your report in word and make tables and graphs in excel. 
• Hand in your assignment with google classroom. 

Introduction

Explain what you are going to do and why.

DONT WRITE 'I am doing this because the teacher said I must do it'. 

Theory

• You make a summary of the theory before you come to the class to do the practical.
  
• Explain all the relevant theory here.
  

Method of measurements

Answer the questions:

• How and with what did you take your measurements?

Also insert a picture of your setup (tip: take the picture before you do anything else) and explain what is in the picture. 

Results of measurements

In this section you write up the resuts you find. 

Tables and graphs you must make in EXCEL. 

Dont include your calculations here. That comes in the next section under calculations. 

Calculations

Show your calculations here. 

If graphs and tables are needed here, ensure that you make these in EXCEL. 

Conclusion and recommendations

• Here you will interpret the calculated values. 
  
• That means means that you will explain what the results mean, and if it is correct. 
  
• Explain why it is correct, or why it is not correct.
  
• Also write what you could have done better. 
  

In a nutshell:

N=​v​​b​​

N=​V​​B​​