Chapter 2 Physics

Question 1

physics

Answer 1

the science of matter and energy and the interactions between them.

the study of matter, motion, movement and the world around us.
helps us describe the word and the interaction of objects in that world.

Question 2

magnitude

Answer 2

quantity (extent) of a property of the object.

Question 3

every physical measurement consists of two elements

Answer 3

1-Magnitude

2-Unit

Question 4

distance (d)

Answer 4

the length of the shortest line connecting two points.

unit most often used- meter

Question 5

SI

Answer 5

international system of units

Question 6

area (A)

Answer 6

the amount of space occupied by a surface (2 dimensional)

it is reported in square units such as meters squared
LOOK AT NOTES PG 8 FOR FORMULAS

Question 7

volume (v)

Answer 7

the amount of space occupied by a substance or an object. (3 dimensional)

it is reported in cubic units such as meters cubed.
LOOK AT NOTES PG 8 FOR FORMULAS

Question 8

mass (m)

Answer 8

the amount of matter that is present in a substance.

reported in kilograms for larger masses and grams for smaller masses

*mass stays the same on earth or moon. it is constant

Question 9

weight

Answer 9

the weight of an object is the force of gravity acting on the object.
weight=mass x gravity

weight varies based on gravity

Question 10

gravity on Earth

Answer 10

9.8 m/s squared 2.12 in textbook (pg 9 of notes)

Question 11

density (p)

Answer 11

the amount of matter in a given unit of VOLUME.
p=mass/volume
reported in kg/cm cubed

Question 12

elasticity

Answer 12

the property that allows matter to recover its size and shape after it has been expanded or compressed.

elasticity is needed for sound to be created and for sound to travel air pocket behind eardrum. equalized with the outside air pressure when you yawn, swallow or chew (eustachian tube)

Question 13

kinematics

Answer 13

the branch of physics that describes the motion of objects in space without considering the cause of the motion.
the focus of kinematics is the relationship among displacement (d), velocity (v), acceleration (a), and time (t)

Question 14

vector

Answer 14

represented by an arrow with a specific magnitude, a unit, and DIRECTION.

Question 15

displacement (d)

Answer 15

a change in position
reported in meters

the distance from the original position to the final position, not the path taken to get there.

Question 16

velocity (v)

Answer 16

the rate of displacement
reported in meters per second (m/s)
LOOK AT NOTES FOR FORMULA (pg 11) 2.2 and 2.3 book

Question 17

momentum (M)

Answer 17

the product of mass and velocity of a moving object.
M= m x v (mass x velocity) PG 11 NOTES

the total momentum of a system does not change its value. it is a converted quantity that is used to predict the outcome when objects bounce into one another.

Question 18

acceleration (a)

Answer 18

rate of change in velocity.
reported in meters/ seconds squared
LOOK AT NOTES FOR FORMULA (pg 11) 2.4 book
a= velocity/time
acceleration due to gravity on Earth =9.8 meters/seconds squared. (pg 11 notes/ fold out)

Question 19

dynamics

Answer 19

the study of the effects of forces on the state of an object or a system of objects.

study of energy

Question 20

force (F)

Answer 20

a push or a pull
reported in newtrons (N)

force = mass x acceleration (pg 12 notes.) 2.9 book

Question 21

newtron

Answer 21

the amount of force required to accelerate a 1kilogram mass at 1 meter per second squared.
substitute kg x m per second squared for Newtron.

Question 22

Newton’s First Law of Motion (Inertia)

Answer 22

an object at rest will remain at rest and and object in motion will remain in motion and move with uniform velocity unless acted upon by an external force.

Question 23

Newton’s Second Law of Motion

Answer 23

an object’s acceleration is proportional to the force exerted on the object and inversely proportional to the mass of the object .
force=mass x acceleration.

Question 24

Newton’s Third Law of Motion

Answer 24

for every action there is an equal and opposite reaction.

Question 25

Law of Conservation of Momentum

Answer 25

extension of Newton’s laws.

when objects collide, the sum of the momenta of the objects before the collision must be equal to the sum of the momenta after the collision.

Question 26

Newton’s Law of Universal Gravitation

Answer 26

gravity is a universal phenomenon that any two objects in the universe attract each other.

the attraction strength depends on the masses and the distance between them.
notes page 13.
text pate 39.

Question 27

work (W)

Answer 27

the effect of force (F) moving an object over a distance (d)

W=F x d
if displacement does not occur, then no work is cone on an object.
reported in Joules (J)
1J= the amount of work done when a 1kg mass is moved 1m.

Example 
W=Fxd
W=5Nx3m
W=15Nxm
W=15J

Question 28

energy

Answer 28

the ability or capacity of an object to do work.
reported in Joules (J)
energy is stored in an object and is gradually expended when the object does work.

if we want the object to do more work, we need to provide the object with more energy. therefore, work and energy can be treated as the same physical property seen from two different points of view.

**Energy is future work, whereas work is used energy.

Question 29

potential energy (Ep)

Answer 29

the energy of an object due to its position within a given physical system or environment.

gravity is the main source of potential energy, but not the only one.
elasticity is also a source of potential energy

Ep= mass x gravity x height

Question 30

kinetic energy (Ek)

Answer 30

the energy of motion that is carried by an object due to its velocity.
the faster an object is moving, the greater its kinetic energy.

Ek= (mass x velocity squared)/2

Question 31

law of conservation of energy

Answer 31

energy can change from one form to another, but can’t be created or destroyed.

Question 32

Power (P)

Answer 32

the rate at which a system is gaining or losing energy
reported in watts (W)

energy expended over time.

P=work/time=Energy/time

thus, the power of a system that does 50J of work in 30 seconds is greater that the power of a system that does 50 J of work in 5 minutes.

Example: if 100J of work is done over 10 seconds, what is the power.
P=100J/10s
P=10 J/s= watts
P=10W

Question 33

watt

Answer 33

the ability of the system to do 1 Joule of work in 1 second.

Question 34

Converting between metric units

Answer 34

-from a unit WITH a prefix to a base unit multiply by the
decimal equivalent

-from a BASE unit to a unit with a prefix, divide by the
decimal equivalent.