REVIEW QUESTIONS FROM YESTERDAY

What is the area of physics that is most relevant to the following situation?

1. A high school football game2. Food preparation for lunch3. Lightning in a thunderstorm4. Wearing sunglasses outside

REVIEW QUESTIONS FROM YESTERDAY

What is the area of physics that is most relevant to the following situation?

1. A high school football game mechanics; b/c the ball is moving, spinning object

2. Food preparation for lunch thermodynamics, b/c cooking involves increasing temperature

3. Lightning in a thunderstorm electromagnetism b/c lightning is a form of electricity

4. Wearing sunglasses outside optics, b/c sunglasses have lenses to decrease the light that reaches your eye

MEASUREMENTS 1-2

READ LAST PARAGRAPH IN PG. 10 AND CONTINUE TO PG. 11. “SI IS THE STANDARD MEASUREMENT SYSTEM FOR SCIENCE.

Explain the figure and simplify this section in your notes with (1-3) sentences

SI USES PREFIXES TO ACCOMMODATE EXTREMES

King Hector Drinks Bad dark chocolate milk

SI USES PREFIXES TO ACCOMMODATE EXTREMES

100 000 000 000 000 000 m = _____________?

0.000 000 001 m = ____________?

The mass of a mosquito = 0.01 g = ________kg = ________mg

SI USES PREFIXES TO ACCOMMODATE EXTREMES

1mm / 10-3m = ______________?

37.2 mm x 1mm/10-3m = ____________?

37.2 mm x 10-3m/1mm = ____________?

PG. 5: TABLE 1-1

PG. 6 TABLE 1-2

PRACTICE PROBLEMS PG. 7 5-8

WHAT IS THE DIFFERENCE BETWEEN ACCURACY AND PRECISION?

Get into 2 groups. One at a time each of you measure the

length of the lab table with one person’s shoe. Do not share results with others in your group until everyone has measured the table.

Compare the accuracy of each measurement Does the shoe have precision?

WHAT IS THE DIFFERENCE BETWEEN ACCURACY AND PRECISION?

Now measure the table with a meterstick one at a time and then compare a 2nd time

Compare the accuracy of your measurement Does the ruler have precision

Accuracy - how close a measured value is to the true value of the quantity measured;

Ex. If a ruler is worn at the edge the measurer may not make an accurate measurement

Precision – the degree of exactness with which a measurement is made and stated;

Ex. by adding more marks on a tool helps increase precision

RULES FOR SIG FIGS

Zeros between other nonzero digits are significant.

Zeros in front of nonzero digits are not significant

Zeros that are at the end of a number and also to the right of the decimal are significant

Zeros at the end of a number but to the left of a decimal are not significant unless the decimal point is present or measured by you in a lab situation

RULES FOR CALCULATING WITH SIG FIGS

Addition or Subtraction Final answer should have the same number of

digits to the right of the decimal as the measurement with the smallest number of digits to the right of the decimal

Multiplication or division The final answer has the same number of

significant figures as the measurement havin gthe smallest number of significant figures

RULES FOR ROUNDING WITH SIG FIGS

Round down

Whenever the digit following the last sig fig. is a 0, 1, 2, 3, or 4

If the last sig. fig. is an even number and the digit is a 5, with no other nonzero digits

RULES FOR ROUNDING WITH SIG FIGS

Round Up

Whenever the digit following the last sig fig. is a 6, 7, 8, or 9

If the digit following the last sig fig is a 5 followed by a nonzero digit

If the last sig fig is an odd number and the next digit is a 5, with no other nonzero digits