Chapter 1 & 2

Question 1

SI Unit of length

Answer 1

meter

Question 2

Definition of length

Answer 2

the distance light travels in a vacuum in a certain amount of time

Question 3

SI Unit of mass

Answer 3

kilogram

Question 4

Definition of a kilogram

Answer 4

the mass of a specific platinum-iridium cylinder in France

Question 5

SI Unit of time

Answer 5

second

Question 6

definition of a second

Answer 6

the periods of radiation from cesium-133 atoms

Question 7

Accuracy

Answer 7

a description of how close a measurement is to the correct or accepted value of the quantity measured

Question 8

Precision

Answer 8

the degree of exactness of a measurement (how much are you rounding?)
Describes the limitations of the measuring instrument
Significant figures help keep track

Question 9

Sig Figs Rules

Answer 9

• Nonzero digits are always significant
• All final zeros after the decimal are significant
• Zeros between two other significant digits are always significant
• Zeros used solely for spacing the decimal point are not significant
• Multiplication/Division- answer can only have as many significant digits as the least precise of the numbers in the operation (only as many as the least # of sig figs)
• Addition/Subtraction- answer can only be precise to the least precise of the numbers in the operation (least decimal places)

Question 10

One dimentional motion

Answer 10

• a train on a straight track in one direction
• to measure, you must have a frame of reference (a system for specifying the precise location of objects in space and time)

Question 11

Displacement

Answer 11

• a change in position
• =/= distance traveled
• unit is the meter
• = final position － initial position

Question 12

average velocity

Answer 12

• the total displacement divided by the time interval during which the displacement occurred (similar to how fast something is going)
• unit is m/s
• describes motion with both a direction and a numerical value (a magnitude- VECTORS)

Question 13

acceleration

Answer 13

• the rate at which velocity changes over time
• An object accelerates if its speed, direction, or both change
• has direction and magnitude. Also a vector quantity
• When the velocity is constant, there is none
• When the velocity in the positive direction is increasing, it is positive
• When the velocity in the positive direction is decreasing, it is negative.

Question 14

Motion with constant acceleration

Answer 14

• When velocity changes by the same amount during each time interval, acceleration is constant (like gravity)