Problems worked out Chap 2 Physics 101 Lecture

2. How many liters are in a half-gallon of milk? How many liters in half a gallon of milk?

If I had not access to Online Conversions but knew that 1 pint [US, liquid] = 473.176 475 milliliter = 1.893 liters This is called a dimensional analysis

Problem #7 Chapter 2 Veronica was doing a laboratory assignment in which she was investigating the tie of descent, final speed, acceleration, and incline angle of a marble rolling down an inclined track and how each was related to the other. Her data are given next. Incline Angle Time of Descent Final Speed Accleration (degrees) (seconds) (m/s) (m/s)/s 5 3.75 3.2 0.85 10 2.65 4.5 1.70 15 2.17 5.5 2.54 20 1.89 6.3 3.4 30 1.56 7.6 5.08 Express any trends or patterns with words Display the equation in graphical form c. Express any trends or patterns in an equation with words

Spreadsheet Looks like this As far as the angle and the acceleration are concerned there is an excellent fit (R2 = 1). The angle is on the x axis and the acceleration on the y axis We can say that the graph represents the acceleration as a function of the angle (x variable) This represents a linear or a direct relationship between the acceleration and the angle

Final Speed versus Angle of Incline A Polynomial Fit or a power law relation

Here I forced a linear relationship to the trend line the R value is not so good

What is the definition of “Physics” Webster’s 9th new Collegiate Dictionary gives: physics [physica, pl, natural science, fr. Gk, of physikos of nature … ] 1. a science that deals with matter and energy and their interactions in the fields of mechanics, acoustic, optics, heat, electricity, magnetism, radiation, atomic structure, and nuclear phenomena

The Game of Physics Physics is much like playing a game. The game is to find the rules of nature. We cannot always understand why the rules are what they are, but we can still play the game and test the rules as we play. We test the rules with experiments. Mathematics is used a lot in physics because it communicates the rules of the game in a precise and concise way. As with any other language knowing what certain words and symbols mean is important. For example c is used frequently for the speed of light (3 x 108 m/s) or 300 million meters/second.