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”

When an object has measurable sides Measuring When an object has measurable sides

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

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

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

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

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

L=1.27 cm W=1.27 cm H=5 cm digital calipers L x W x H 1.27 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 1.27 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 3.14 x 0.642 x 5 6.1 cm3 d= 1.27 cm H=5 cm digital calipers V= π r2h 3.14 x 0.642 x 5 6.1 cm3 d= 1.27 cm H=5 cm

Measuring Mass - Calculating Density LEARNING TARGET: I can mathematically determine an object’s density using its mass and volume. OCT 4 / 5 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"

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)

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

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”)

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

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) show videos