Terms Lecture 1

Question 1

Mass

Answer 1

amount of matter in an object

Question 2

Matter

Answer 2

Anything physically ready

Question 3

Weight

Answer 3

Measures the force with which gravity pulls on an object

Question 4

Area

Answer 4

Length times length

m²

Question 5

Volume

Answer 5

Area times length

m³

Question 6

Density

Answer 6

Mass per unit volume

kg/m³

Question 7

Speed

Answer 7

Distance in speed per unit time

m/s

Question 8

Acceleration

Answer 8

Change in speed per unit time

m/s²

Question 9

Force

Answer 9

Mass times acceleration

(kg * m)/s²

Question 10

Pressure

Answer 10

Force per unit area

kg/(m*s²)

Question 11

Energy

Answer 11

Force Times distance

(kg*m²)/s²

Question 12

Density Properties

Answer 12

A. Temperature depedent property - most substances expand when heated and contract when cooled

B. Use property - allows conversion of a liquid’s volume to mass

Density is comtimes confused with a mass, a kg of feathers weigh the same as a kg of gold but gold occupies less space because it has greater density

Density = Mass/volume

Question 13

Energy vs Kinetic Energy

Answer 13

Energy : A. Capacity to do work or supply heat

B. Energy = work + heat

Kinetic Energy: A. Energy of motion

B. E_k = 1/2(mv²)

Question 14

Units of Energy

Answer 14

Joule

Calorie

Question 15

Accuracy

Answer 15

How close a measurement is to the true value

Question 16

Precision

Answer 16

how close repeated measurements are to each other

Question 17

Significant Figures

Answer 17

Defined: Total number of digits recorded for a measurement

• Generraly the last digit in a reported measurement is uncertain(estimated)
• Exact numbers and relationshiops ( 7 days in a week, 30 students in a class, etc) effectively have an infinite number of significant figures

Question 18

Significant Figures Rules

Answer 18

1. Zeros in the middle of a number are like any other digit; they are always significant
2. Zeros at the beginning of a number are not significant(placeholders)
3. Zeros at the end of a number and after the decimal point are always significant
4. Zeros at the end of a number and before the decimal point may or may not be significant

Question 19

Sig Fig rules in calculations

Answer 19

Multiplication or Division : The anser can’t have more significant figures than any of the original numbers

Addition or subtraction: The answer can’t have more digits to the right of the decimal point than any of the original numbers

Question 20

Rules of rounding

Answer 20

5. 00 Round Down
6. 000001 Round up

Question 21

Dimensional analysis

Answer 21

A mthod that uses a conversion factor to convert a quantity expressed in one unit to an equivalent quantity in another unit

Question 22

Conversion Factor

Answer 22

Expresses the relationship between two different units

Orginal Quantity x Conversion Factor = Equivalent quantity