2. Let’s debrief your volume work from Activity 8 last class.
get out WS 8.1b/c
we need to all be “on the same page” now or all future work will be “off”

3. When an object has measurable sides
Measuring
When an object has measurable sides

4. ruler ruler ruler ruler ruler ruler 7.2 cm3 7.2 cm3 V =𝜋𝑟2ℎ 5.7 cm3
L=1.2 cm W=1.2 cm H=5 cm
L x W x H
1.2 x 1.2 x 5
7.2 cm3
L x W x H
1.2 x 1.2 x 5
ruler
L=1.2 cm W=1.2 cm H=5 cm
7.2 cm3
L=2.5 cm W=2.5 cm H=2.5 cm
ruler
L x W x H
2.5 x 2.5 x 2.5
15.6 cm3
L=2.5 cm W=2.5 cm H=2.5 cm
L x W x H
2.5 x 2.5 x 2.5
ruler
15.6 cm3
V =𝜋𝑟2ℎ
ruler
5.7 cm3
D= 1.2cm H=5 cm
3.14 x .62 x 5
V =𝜋𝑟2ℎ
ruler
D= 1.2 cm H=5 cm
5.7 cm3
3.14 x .62 x 5

5. When an object does not have measurable sides
Displacement
When an object does not have measurable sides

6. N/A N/A 8 mL 8 mL 6 mL 6 mL Vf-Vi 38 – 30 Vf-Vi 38 – 30 Vf-Vi 36 – 30
Vi=30 mL Vf=38mL
8 mL
displacement
Vf-Vi
38 – 30
Vi=30mL Vf=38mL
8 mL
displacement
N/A
N/A
Vf-Vi
36 – 30
6 mL
displacement
Vi=30 mL Vf=36mL
Vf-Vi
36 – 30
Vi=30 mL Vf= 36mL
displacement
6 mL

7. If you use a tool capable of more accuracy (on target) and precision (repeated accuracy), you will get better measurements/results.
best tool:
digital calipers

8. digital calipers
If you use a tool capable of more accuracy (on target) and precision (repeated accuracy), you will get better measurements/results.

9. L=1.27 cm
W=1.27 cm
H=5 cm
digital
calipers
L x W x H x 1.27 x 5 =
8 cm3
L=1.27 cm
W=1.27 cm
H=5 cm
digital
calipers
8 cm3
L x W x H x 1.27 x 5 =
L=2.54 cm W=2.54 cm H=2.54 cm
digital
calipers
L x W x H
2.54 x 2.54 x 2.54 =
16.4 cm3
L=2.54 cm W=2.54 cm H=2.54 cm
L x W x H
2.54 x 2.54 x 2.54 =
digital
calipers
16.4 cm3
digital
calipers
V= π r2h x x 5
6.1 cm3
d= 1.27 cm H=5 cm
digital
calipers
V= π r2h x x 5
6.1 cm3
d= 1.27 cm H=5 cm

10. Measuring Mass - Calculating Density
LEARNING TARGET: I can mathematically determine an object’s density using its mass and volume.
OCT 4 / Activity A9
Measuring Mass - Calculating Density
CHALLENGE Q:
How can mass and Volume of an object be used to calculate its Density?
DISCUSSION:
vocab:
mass weight Volume Density
changes due to gravity
= mass
volume
"stuff"
"space"

11. Quick observation of light and dark metals?
DISCUSION (cont’d)
Quick observation of light and dark metals?
dark version was more mass (heavy)
2. Prediction: which one (light or dark)
will have greater density? (write yours)

12. PROC and DATA: Materials: Procedure: A-37-39 DATA: WS 9.1 / 9.2
(if done early Read and Think only)
ANALYSIS:
A-40 Q 2

13. Does density change if size changes?
Post Discussion:
Does density change if size changes?
Demo Q:
If rock with mass 10g and Volume 5cm3 (Density = 2g/cm3) is cut in half, what will be the Density of the two new pieces of rock?
Explain:
NO!
if Volume changes, then mass will change proportionately
(the same “amount”)

14. ANALYSIS:
A-40
Q 2
safety precautions for unknown materials are:
goggles (usually always)
gloves (avoid touching)

15. How can mass and Volume of an object be used to calculate its Density?
ANSWER CHALLENGE Q:
How can mass and Volume of an object be used to calculate its Density? A:
HW:
Analysis A-40 Q 3 a-e (20pts, next class)
HINT: write Formulas and SHOW all work
HINT: 3e needs two diagrams (before and after) along with labels, computation and explanation
*use SEPUP website to find questions if needed
* Unit A TEST (11 / 12 OCT)
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