Physical Science Lab Chapter 14 PDF

Preview

Summary

Physical Science Lab Work Chapter 14...

Description

Units and Significant Figures PRE-LAB QUESTIONS 1. You are casually communicating how chilly it is outside to a friend who lives in another country. What would be the most standardized way to describe the weather? a. 5-‐layers-‐of-‐clothing cold b. Turn-‐up-‐the-‐thermostat-‐to-‐high cold c. Below-‐freezing cold d. Tooth-‐chattering cold

2. Which of the following is recognized as an SI unit? a. Barrel b. Lunar Year c. Kilometer d. Arm’s Length

3. What best describes an AU to three significant figures? a. 149 m b. 1.49 × 1011 m c. 149.597 × 109 m d. 149,597,870.7 × 103 m

4. Which two objects would exert the most gravitational pull on each other? a. Two identical stars that are 2 pc apart. b. Two identical stars that are 0.5 pc apart. c. Two identical stars that are 4 pc apart. d. Two identical planets that are 0.5 pc apart.

©eScience Labs, 2017

Units and Significant Figures EXERCISE 1: ANALYZING AND REPORTING DATA Data Sheet Table 4. Handspan Measurements Average Span (mm)

Measuremen t#

Handspan (mm)

1

203.2mm

1.25mm

1.56mm

2

196.9mm

-5.05mm

25.50mm

3

203.2mm

1.25mm

1.56mm

4

209.6mm

7.65mm

58.52mm

5

196.9mm

-5.05mm

25.50mm

�i

x

�i – x

( �i –

x )2

201.95mm 6

203.2mm

1.25mm

1.56mm

7

203.2mm

1.25mm

1.56mm

8

196.9mm

-5.05mm

25.50mm

9

203.2mm

1.25mm

1.56mm

10

203.2mm

1.25mm

1.56mm

Standard Deviation of Table 4 Measurements (mm): +/-3.8mm

Average Handspan (m): .20195m

Standard Deviation of Handspan (m): +/- .0038m

Final Handspan (m): .20195m

©eScience Labs, 2017

Units and Significant Figures Table 5. Time of Flight Measurements Measuremen t#

Time of Flight (s)

Average Time of Flight (s)

�i

x

1

1.57s

-.06s

.0036

2

1.60s

-.03s

.009

3

1.67s

.04s

.0016

4

1.65s

.02s

.004

5

1.61s

-.02s

.004

.00s

.000

1.63s

�i – x

( �i –

x )2

6

1.63s

7

1.66s

.03s

.009

8

1.59s

-.04s

.0016

.04s

.0016

.01s

.001

9 10

1.67s 1.64s

Standard Deviation of Table 5 Measurements (s):.0333s

Final Time of Flight (s): 1.63s

©eScience Labs, 2017

Units and Significant Figures Table 6. Mass Measurements Average mass (g)

Measuremen t#

Mass (g)

1

4.55g

-.036g

.001296g

2

4.55g

-.036g

.001296g

3

4.58g

-.006g

.000036g

4

4.58g

-.006g

.000036g

5

4.58g

-.006g

.000036g

�i

x

�i – x

( �i –

x )2

4.586g 6

4.60g

.014g

.000196g

7

4.60g

.014g

.000196g

8

4.60g

.014g

.000196g

9

4.61g

.024g

.000576g

10

4.61g

.024g

.000576g

Standard Deviation of Table 6 Measurements (g): .021071g

Average Mass (kg): .004586kg

Standard Deviation of Mass (kg): 2.1071x10-5kg

Final Mass (kg): .004586kg

©eScience Labs, 2017

Units and Significant Figures Exercise 1 Post-Lab Questions The Gravitational Constant, G, is 6.674 × 10-11 m3/kgs2. Using Equation 3 below, what is the force of gravity (Fg) between you and a table that is 2 meters away, assuming your table weighs 20 kg? Remember to convert your weight to kg (1 lb. = 0.45 kg). Show your work, and report your answer with 3 significant figures. 195lbs = 87.75kg F = 6.674 x 10-11 x 20 x 87.75 = 2930x10-11 22

Using Equation 3, what is the force of gravity between you and Earth, assuming all of the Earth’s mass is at its center and you are standing at sea level? The mass of the Earth is approximately 5.900 x 1024 kg. At sea level, the distance to the center of the Earth is approximately 3,959 miles. Be mindful of your units, and show your work. Report your answer with four significant figures. 195lbs = 87.75kg 3959 miles = 6371392.9 meters F = 6.674 x 10-11 x

5.900 x 1024 x 87.75 =

85090000000000x10-11

6371392.92

How heavy would your table have to be for you to be preferentially drawn to it instead of the Earth? Assume you are standing 2 meters away from the table. Show your work, and report your answer with three significant figures. Gravity Acceleration = 9.81m/s2 Distance = 2 meters G = 6.674 × 10-11 m3/kgs2 G X (mass of Table) = Gravity Acceleration D2 6.674 × 10-11 x mass of table = 9.81 22 Mass of table = 9.81 x 4 = 5.88 x 1011 -11 6.674 × 10

©eScience Labs, 2017...