Mr. Gazy Khatmi .R ALBEDRI

Practical physics Objectives

The purpose of the practical physics is to link the theoretical study with applied .

- To investigate the laws .- To determined the value (e.g. the value of the

gravity constant , refractive index of water etc - To get skill of how to deal with tools and devices

What is an Experiment?

A test under controlled conditions that is made to demonstrate a known truth, examine the validity of a hypothesis, or determine the efficacy of something previously untried.

Multiple choice

A. To prove what I know is rightB. To prove that he is wrongC. To test an ideaD. To see what happensE. All of the above

Measurement Measurement : when you visit the doctor for a checkup, many measurements are taken: your height, weight, blood pressure, and heart rate. Even your vision is measured and assigned a number.

Physical Quantities and it Measurements :

The physical quantities divided to two type : 1- Fundamental quantities (e.g. Time ,Temperature ,

Length etc) 2-Non Fundamental quantities (e.g. acceleration ,Area etc

Errors Systematic errors (Regular errors)

An error that remains constant through out an experiment and cannot therefore be detected. For instance: Hardware

Lets look at our ruler again.

Random errors One form of scale-reading error that often afflicts beginners in the science laboratory is failure to properly align the eye with the part of the scale you are reading. This gives rise to random error. Random refers to the change in the apparent position of an object when viewed from different points.

Zero Error It is the incorrect

reading that you have on your instrument when it is measuring something that *you know* should read zero. 

The Graph

QUESTION ANSWER

1. What is the title of this line graph?   

Temperatures in New York City

2.What is the range of values on the horizontal scale?

1 to 6

3.What is the range of values on the vertical scale?

0 to 80

4. How many points are in the graph?    6

5.What was the lowest temperature recorded?

43° F

6.What was the highest temperature recorded?

67° F

7.At what point did the temperature dip?

Day 3: 50° F

Accuracy and precisionWe tend to use these two terms interchangeably in our ordinary conversation, but in the context of scientific measurement, they have very different meanings:

Accuracy refers to how closely the measured value of a quantity corresponds to its “true” value.

Precision expresses the degree of reproducibility, or agreement between repeated measurements.

Example:

• ______?• Not • ______?

• Not • ______?• ______?

• Accurate and

• Precise

How to write lab report : 1- Objective , Aim or goal 2- Apparatus 3- Theory 4-Results 5-calclations 6-concolustion

Requirements in laboratory Lab coat scientific calculator A box of Engineering