Length+and+time,+Density

// ** 1.1 Length and time ** // LOs: • Use and describe the use of rules and measuring cylinders to find a length or a volume • Use and describe the use of clocks and devices, both analogue and digital, for measuring an interval of time • Understand that a micrometer screw gauge is used to measure very small distances
 * Supplement **

1. What are the lab equipment that you have chosen to measure? 2. What sort of things have you used to measure the lab equipment? 3. Do you know what is the most distance galaxy ever measured? Can you measure the distance using a regular ruler? What measurement do you use? What is the unit of it? 4. Do you think they are reliable for accurate or precise measurement? 5. What can you think of to prevent any  ‍‍‍‍mistakes/errors ‍‍‍‍ to measure a material?
 * Activity **
 * Measure at least 5 lab equipment without using any measuring device such as a ruler, measuring cylinder. **


 * Task **
 * Find the thickness of your notebook paper and the size of a head of iron nail. **

Caliper: an instrument for measuring the distance between two points media type="youtube" key="vkPlzmalvN4" width="560" height="315" Classwork ( 15th Aug. 2016) ; 1. Make a list of the SI Units if you have not done yet. 2. Learn how to use a vernier caliper and micrometer. 3. Describe the 2 uses of a mechanical method for the measurement of a small distance. 4. Measure and describe how to measure a short interval of time such as the period of a pendulum. || [|How to use a micrometer?] from Youtube.com media type="youtube" key="StBc56ZifMs" width="560" height="315" Warning: In this video, milimeter should be in **mm**, not in MM
 * [|How to Read a Metric Vernier Caliper]? [|WeldNotes.com] Published on 10 Feb 2017

Homework by Wednesday 16 Aug 1. Read text p14, 15 and take notes 2. Do questions 1, 2 and 3 (p15) || Read [|Significant figures] from GCSE Bitesize (you can click the link) and complete 5 questions on the website. There will be short quiz, to check your homework and your understaning about Significant figures, on Monday. The score you achieved from the quiz will be reflected to your report cards.
 * Homework 18th August 2017. **

LO: • Obtain an average value for a small distance and for a short interval of time by measuring multiples (including the period of a pendulum) (Average) || T 2 ||
 * Pendulum Experiment **
 * Length || Time for 20 oscillations || Period
 * L/m || trial 1, trial 2, trial 3, etc. T/s || T/s || T 2 /s 2 ||
 * ** 0.500 ** || Make 2 trials for each length. ||  ||   ||
 * ** 0.600 ** ||  ||   ||   ||
 * 0.700 ||  ||   ||   ||
 * 0.800 ||  ||   ||   ||
 * 0.900 ||  ||   ||   ||
 * ** 1.000 ** ||  ||   ||   ||
 * 1.100 ||  ||   ||   ||
 * ** 1.200 ** ||  ||   ||   ||

(Average) || T 2 || [|Simple pendulum] from hyperphysics.phy-astr.gsu.edu
 * Length || Time for 20 oscillations || Period
 * L/m || trial 1, trial 2, trial 3, etc. T/s || T/s || T 2 /s 2 ||
 * ** 0.500 ** || Make 2 trials for each length. ||  ||   ||
 * ** 0.600 ** ||  ||   ||   ||
 * 0.700 ||  ||   ||   ||
 * 0.800 ||  ||   ||   ||
 * 0.900 ||  ||   ||   ||
 * ** 1.000 ** ||  ||   ||   ||
 * 1.100 ||  ||   ||   ||
 * ** 1.200 ** ||  ||   ||   ||

__ //Q1. Describe how you would find the thickness of a sheet of paper by using a micrometer.// __ Check zero point. Close micrometer onto paper. Lock the micrometer. Take the reading of both scales of barrel and thimble.

__ //Q2. Describe how you can make the above experiment a fair test.// __ Try the above procedure several times. Measure the thickness of paper using several sheets of paper then divided it by the number of piece of paper.

__ //Q3. Describe// __// __and explain__ // __ why //how// //you would determine the period as accurately as possible.// __ Measure the time for 20 complete oscillations, divide the measured time by 20. The reason why we measure the time for 20 swings then divides it by 20 is to make the measurement more accurate.

=// 1.4 Density //= LO: • Recall and use the equation ρ =m/V • Describe an experiment to determine the density of a liquid and of a regularly shaped solid and make the necessary calculation • Describe the determination of the density of an irregularly shaped solid by the method of displacement • Predict whether an object will float based on density data

The density of an object is relative to two things; It can be calculated like this; Image from [|http://erinschumacher.com]
 * MASS
 * VOLUME

m is mass, V is volume || Units of density are kg/m 3, kgm - 3 or g/cm 3
 * =**//ρ//**=
 * m/V**= || where //ρ (rho)// is density,

Example) 2000 kg of water occupies 2m3 of volume  Its density is  ρ = 2000/2 = 1000kg/m 3


 * Activity **
 * Measure the density of different materials such as a rock, milk, an apple and a piece of toast bread. **


 * Task **
 * Design a practical write up to investigate the density of different 3 materials including a solid, a solid in irregular shape and liquid material). **


 * Extension: **
 * Describe the determination of the density of an irregularly shaped solid by the method of displacement, and make the necessary calculation **

Density from [|Eureka episode] media type="youtube" key="iQuNizENtaQ" width="560" height="315" [|Eureka!] [|Episode 25 Volume & Density] [|farrahannedhaliwal] Published on 25 Feb 2012

Homework by Wednesday 1. Do questions on the text 2. Complete the practical write up on density investigation that you designed during the class.

Homework by Monday 1. Make a summary after reading the text 2. Complete the end of chapter questions of unit 1. 3. Submit your practical write up on density investigation.

__ //Q1. What precaution should be taken when using a measuring cylinder?// ____ Make sure that the measuring cylinder is vertical. Make sure that the eye is levelled with the liquid surface(meniscus), avoiding parallax error.