cahier physique - physics workbook

1) INTRODUCTION

When things get bigger something very strange happens. For example imagine we hanging out with Sponge Bob. He lives int the sea, he is not very big - about 10 centimeters tall. Here he is now !

One of the great things that you will notice about Sponge Bob is his body is a rectangle/ That means we can figure out his volume. It's easy.
You instructor will give you a clone of Sponge Bob.
First a review. What linear dimensions mean ? ________________________________________-
________________________________________________________________________
Let's find the linear dimension of the clone. Get a ruler.
Sponge Bob height = ___________ cm
Sponge Bob length = ____________ cm
Sponge Bob width = ______________ cm

So , what's his total volume in cm³ ? __________

We are going to suppose that the density of Sponge Bob is 10g/cm³
That means that if we cut (under surgery, with anesthesia) 1 unit cube 1cmx1cmx1cm (a small cube with a width = 1cm,
length = 1cm, height = 1cm), the plate scale will read __________g.
This is when he is wet. The density is greater than water's density (1g/cm³), that's why spongebob can sink.

But what would happen if he gets bigger ? let's say he was twice as tall , 3times as tall , 5 times as tall.
Le'ts think of a SUPER SPONGE BOB 10 times as tall .what would happen to its mass ? ___________________________
Let's see if you are right. Fill the table below.

	height	length	width	volume	mass (g)= density x volume	Compare to regular Bob, the mass is multiplied by ___________
regular Bob	_____	________	________	_______	_________	____________
Twice as tall	________	_______	________	_______	___________	__________
3 X as tall	______	_________	_______	________	____________	____________
5 X as tall	_______	__________	_______	_______	____________	____________
Super Sponge Bob 10 X as tall	_______	________	_________	_______	_______________	__________

Super Sponge Bob is ___________ times taller than regular Sponge bob but, has ______________times the mass of regular Sponge Bob.
What would happen to him. write a short story.

GOING FURTHER

1)(Remember what happens to the volume and surface when a shape is scaled up)
For a model of the solar system to be accurate, the Sun's diameter would need to be about 612 times the diameter of Pluto.
How would their volumes related ? (is it multiply by 612 ? 612² ? 612³ ? )

2) If the linear scale factor of a model is 1/4.
(meaning you scale down the mode by dividing each side (length) my 4. Each linear dimension like length is divided by 4).
What is the relationship between the volume of the original object and the volume of the model.
(the volume is divided by ... )

3) Let's say it takes 100,000 lego blocks (blocks are like units cubes in the cube you built)
to build a cylinder monument.
A) suppose 1 lego is 1 unit of volume. So the volume of the cylinder = _________
B) If you scale up your model (keeping the same proportion) 2 times, how many legos would be needed to build
you new model ? (the liner dimensions like the diameter and the height is multiplied by 2)

4) A piece of pottery requires 2 pounds of modeling clay.
(pounds it a unit for weight and weight behaves like volume when you scale up or down a model).
How much clay would required to double all the dimensions of the piece ?
(you multiply all the lengths by 2). refer to the lab3)

5) At Toby World Square, a theme park in Japan, there are more than 100 scale models of world famous landmarks,
1/25 the size the size of the originals. (meaning the true building have been scaled down by a factor of 25. All the lengths are divided by 25)
A) How tall in inches would a scale model of Big Ben's 320 ft clock tower be ?

B) How tall would a 5ft tall person be in the model ?
(convert to inches 1 foot = 12 inches)

6) A DNA model was build using the scale 2cm = 10^-7 mm
that means that 2cm in your scaled up model = 0.0000001 mm in reality.
(you multiply the length of DNA by 210⁷ to get your model)
If the model of the DNA is 17cm long, what is the length of the actual chain? follow the steps below.
hint: A) build a proportion table:

model (cm)	reality (mm)
2	10^-7
17	x

B) convert mm to cm. answer _______________

7) A model of a 27ft tall house was made using the scale 2 in:3ft.
What is the height of the model

hint: use a table

model (in)	reality ft)
2	3
x	27

8) try without hint please (hide the table)
Under a 1000:1 microscope view, a paramecium appears of have length 39 mm. What is its actual size ?

under microscope mm	reality mm
1000	1
39	x