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Attendance

Ms. Doshi

Physics Chapter 1

• Dimensions show the physical nature of a quantity:– Length = L = [x]

– Mass = M = [m]

– Time = T = [t]

• Brackets [ ] show dimensions of a physical quantity.

• You can treat dimensions like algebraic quantities. Look at the board.

Dimensional Analysis

Korean Textbook: Example 1.1Find an equation.

Exercise 1.1, Give simple question for students because not in Korean textbook.

Students answer the questions.

• A significant figure is a reliably known digit (other than 0 used to locate a decimal point)

• In multiplying (dividing) two or more quantities, the number of significant figures in the final product (quotient) is the same as the number of significant figures in the least accurate of the factors being combined, where least accurate means having the lowest number of significant figures.

• The textbook uses two or three significant figures.

• When numbers are added (subtracted), the number of decimal places in the result should equal the smallest number of decimal places of any term in the sum (difference).

• Write the examples, from the board, in your notebook.

Significant Figures

Carpet Calculations

Korean Textbook: Example 1.2

Exercise 1.2, Give simple question for students because not in Korean textbook. & students read pages 9 and 10

1 mi = 1609 m = 1.609 km

1 m = 39.37 in = 3.281 ft

1 ft = 0.3048 m = 30.48 cm

1 in = 0.0254 m = 2.54 cm

Conversion of Units

Korean Textbook: Example 1.3Students do exercise 1.5. Give students simple question.

Another Example for students to do. This is NOT in the Korean textbook. Give simple question for students.

Students do exercise 1.4. Give simple question for students.

• Order of magnitude

– The power of 10 that is closest to the actual value of the quantity.

– Examples:

• 103 = 1000, OOM=3

• 75 kg = 102 kg, OOM=2

Order of magnitude

Korean Textbook: Example 1.4

Students do exercise 1.6. Give simple question for students to do.

Korean Textbook: Example 1.5

Exercise 1.8 for students to do. Give simple question for them to do.

• Coordinate system– A fixed reference point 0, called the origin.

– A set of specified axes, or direction, with an appropriate scale and labels on the axes.

– Instructions on labeling a point in space relative to the origin and axes.

• Examples:– Cartesian coordinate system (figure 1.4)

– Plane polar coordinates (figure 1.5)

Coordinate Systems

Cartesian coordinate system

(Figure 1.4)

Plane polar coordinates

(Figure 1.5)

• SOH CAH TOA

• inv sine (sin-1), inv cosine (cos-1), inv tan (tan-1)• set your calculator to degrees not radian

• sin-1 (0.866) = 30°

• Pythagorean Theorem• r2 = x2 + y2

Trigonometry

This is NOT in the Korean Textbook. Ask simple question to students. We will do this example together.

This is NOT in the Korean Textbook. Ask simple question to students. We will do this example together.

Korean Textbook: Example 1.6Do together with students.

Another Exercise for students to do. Give simple question.

Another Exercise for students to do. Give simple question.

• pp 16-17 in Korean Textbook, pp 20-23 in English Textbook

• Problems in English textbook: 5, 9, 11, 13, 15,27, 41, and 49

• Problems in Korean textbook: 3, 4, 5, 6, 7, 12, 17, and 18

• Additional problems in English: Simple questions on board from English textbook: 18, 45, 47

Questions

Goodbye!

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