---------- semester 2-- Freshman
gravity causes... acceleration causes..
objects to accelerate downward, air resistance acts in the direction opposite to the motion and reduces acceleration.
aristotle
one of the first to use observation and logic for discoveries
when converting opposites are
opposite units equal
where are metric units used
other places
aluminum foil cut in half
p
butter melts on warm toast
p
clay molded in a new shape
p
juice box freezes
p
momentum abreviation
p
power abreviation
p
water evaporates
p
momentum formula
p=m*v
example of changing distance
paddle: little pull back big push forward
air resistance force example
parachuting
potential energy abbreviation
pe
what is the potential energy relative to the water surface of a diver at the top of a 10 meter high diving platform. Suppose she has a mass of 50 kilogram?
pe = 4900
potential energy equation (gravitational)
pe=mgh
While on a bike ride, a woman's bike gets a flat tire and she has to push it for 800 meters. She pushes on the bike with a force of 250 N. Calculate the work the woman does on the bike.
200,000 J
steps to solve problem
picture write down what its asking write starting equation rearrange equation plug in values and solve check
magnetic force example
pins on magnet
example of speeding up
plane taking off
another example of constant acceleration
plane taking off with the speed increasing the same amount each second
speed is always
positive
proton
positive inside
Positive slope
positive acceleration
distance is always a
positive number
electrical energy
the energy associated with electric charges
mechanical energy
the energy associated with the motion and position of everyday objects
kinetic energy
the energy of motion
nuclear energy
the energy stored in atomic nuclei
chemical energy
the energy stored in chemical bonds
magnetic force definition
the force a magnet exerts on another magnet, on iron or similar metal, or on moving charges
weight
the force of gravity acting on an object
tension force
the force that is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends.
Gravity Force
the force with which the earth, moon, or other massively large object attracts another object towards itself.
both gravity and air resistance affect
the motion of a falling abject
free fall
the movement of an object toward earth solily because of gravity
Normal Force
the support force exerted upon an object that is in contact with another stable object.
A child pulls a wagon with a force of 60 N. After an unknown distance, the child has done 180 J of work on the wagon. Calculate the distance the child pulled the wagon.
3 meters
A conveyor belt does 3,200 J of work in 80 seconds. Calculate the power of the conveyor belt.
40 Watts
An object has a mass of 6 kg and has a momentum of 50 kg · m/s. Calculate the velocity of the object.
8.3 m/s
a sail boat travels at a speed of 5 m/s for a distance of 400m calculate the time
80 seconds
if there is zero net force then..
the object does not accelerate
efficiency
the percentage of the work input that becomes work output
elastic potential energy
the potential energy of an object that is stretched or compressed
what is horsepower
the power of an engine measured in terms of horses
momentum
the product of an object's mass and its velocity.
work
the product of force and distance. It requires motion and depends on direction
instantaneous velocity
the rate at which an object is moving and direction at a given moment in time
instantaneous speed
the rate at which an object is moving at a given moment in time
acceleration
the rate at which velocity changes
speed
the ratio of the distance an object moves to the amount of time the object moves
pressure force definition
the result of a force distributed over an area
force abbreviation
F
net force equation
F = F1 + F2
air resistance force abbreviation
F air
applied force abreviation
F app
F1= -500N F2=500N F=?
F= 0N
velocity
the speed and direction in which an object is moving
instantaneous acceleration
Is how fast a velocity is changing at a specific instant.
work SI unit
Joule (J)
The molecules in a hot Starbucks coffee are moving at a speed of 234,500 m/s. A molecule of coffee has a mass of 0.5 kg. Determine the type and sub-type of energy the coffee molecules have, and then calculate the amount of energy of this type.
Kinetic Thermal ke= 13,747,562,500
nuclear force definition
the strong nuclear force and the weaker nuclear force act within the nucleus to hold it together
where are imperial units used
U.S.
An extreme bungee jumper leaps off a helicopter and falls downwards.
V I A I I I V V negative
A PERSON JOGS 4.0 KILOMETERS IN 32 MINUTES, THEN 2.0 KILOMETERS IN 22 MINUTES, AND FINALLY 1.0 KILOMETER IN 16 MINUTES. CALCULATE THE JOGGER'S AVERAGE SPEED IN KM/MIN
0.1 ki/min
you travel 35 meters in 60 secongs folloed by 53 meters in 80 second what is the average speed
0.6 m/s
A car begins speeding up to the right from rest to a final velocity of + 5 m/s for a time of 8 seconds. Calculate the car's acceleration.
0.6 m/s2
what is one newton equivalent to
1 N = 1 kg•m/s2
of you go up 30m then to the right 3 s on a graph what is the m/s
10 m/s
the force of rolling friction is about ________ to __________ times less than the force of static or sliding friction
100 1000
A rocket blasts off with an initial velocity of +150 m/s and an acceleration of 45 m/s2 If it travels for 30 seconds, what is the rocket's final velocity?
Vf = 1,500
free (-9.8 m/s2) t (4s) Vf (-52 m/s) Vi (?)
Vi -12.8 m/s
A bus slows down to a stop in 7 seconds. Its acceleration is -0.7 m/s2 . What was the bus's initial velocity?
Vi 4.9 m/s
weight abbreviation
W
On the moon, the acceleration due to gravity is 1.6 m/s2. Calculate the weight of the piece of paper on the moon.
W = 0.016N
On earth, where the acceleration due to gravity is 9.8 m/s2. A piece of paper has a mass of 0.01 kg. Calculate the weight of the paper.
W = 0.98N
If an astronaut has a mass of 112 kilograms, what is her weight on Earth where the acceleration due to gravity is 9.8 m/s2?
W = 1097.6N
what is the relationship between mass and weight
Weight is the product mass and acceleration due to gravity
lift force definition
an upward force due to a pressure difference between the top and bottom of a wing
who are the three scientists
aristotle newton galileo
always remember to put the in displacement equation
arrow
newtons 2nd law
as the net force increases, the acceleration will increase as the mass increases the acceleration will decrease
atomic mass is
at the bottom
atomic number is
at the top
proton # is the same as
atomic number
two types of speed
average speed instantanious speed
difference between average speed and instantaneous speed
average- the total distance divided by the time instantaneous- the rate of an object at a given moment
wedge examples
axe blades on scissors
electrical energy examples
battery flashlight
element symbol is
big letter(s)
thermal energy examples
boiling water heat pack
nuclear energy examples
bomb
A leaf blows in the wind 8 meters to the south and then blows 8 meters to the east. Calculate the leaf's displacement and total distance.
disp= 11.3 SE dis= 16m
Jessica walks 17 meters north. She stops for lunch and then walks 5 meters east. Calculate Jessica's displacement and total distance.
disp= 17.7m NE dis = 22m
tom walks 10m then -7m then 2m. hiw far did he walk
disp= 5m dis= 19m
A fertilizer spreader moves 3 meters to the north and then moves 4 meters to the west. Calculate the spreader's displacement and total distance.
disp= 5m NW dis= 7m
A missile is launched 30 meters to the north and then it turns to travel 60 meters to the east. Calculate the missile's displacement and total distance.
disp= 67.1 NE dis= 90m
A runner jogs 10 meters north and then 20 meters west. Calculate the jogger's displacement and distance.
distance = 30m displacement=22.4 NW
A bird flies 7 meters south and then flies 2 meters west. Calculate the bird's displacement and distance.
distance = 9 m displacement=7.3 m SW
difference between distance and displacement
distance is the length of the path and displacement is the straight line
simple machine examples
door wedge water bottle cap hill
average velocity
the total distance and direction traveled divided by the time it takes to travel that distance
average speed
the total distance traveled divided by the time it takes to travel that distance
thermal energy
the total potential and kinetic energy of all the microscopic particles in an object
constant acceleration
the velocity increases or decreases the same amount each second
as objects fall to the ground
they accelerate and gain speed
what did isaac newton do
tied all the other peoples info together the 3 laws of motion
tension force examples
tire swing
what to look for on graphs
titles
pulley examples
to hoist sails theater curtains
law of conservation of momentum
total momentum before a collision is equal to the total momentum after a collision
element name is
under symbol
air resistances goes
up
positive acceleration
up right
A baseball has a momentum of 45 kg· m/s and has a mass of 0.145 kg. Calculate the velocity of the baseball.
v = 310.3 m/s
velocity equation
v = d/t
work abreviaton
w
weight formula (newton's second law)
w = mg
A girl pulls a wagon to the left with a force of 350 N for a distance of 25m what it the power
w =8,750 J
work equation triangle
w=f*d
power si unit
watt (W)
weight vs. mass
weight is the force of gravity working on a trial mass is the amount of matter in an object
protons determine
what element it is
chemical reaction
when a chemical change takes place
thrust force definition
when a system pushes or accelerates mass in one direction there is a force just as large in the opposite direction
easy thing for inertia
when acted on by an unbalanced force the object tries to keep the same motion as before the force
how is momentum conserved
when objects collide the momentum is passed
what produces energy in chemical energy
when the bonds are broken
what increases thermal energy
when the objects atoms move faster
pressure force examples
when you cut a piece of fruit stop a cut from bleeding pop a pimple needle through cloth when sewing
gravitational force examples
when you flip a pancake you can walk not float when you get your hair cut your hair falls to the ground
__________ is the product of force and distance, and it requires _____________ caused by _________and depends on _______________
work motion force direction
work calculation
work = force * distance
speed is always on the
x axis
distance is always on
y axis
differences between d t graph and v t graph
y axis is different measures two different things
where does the y and x go
y up and down x side to side
yard thing
yd
A bowling ball (7 kg) and a tennis ball (1 kg) have a collision. Before the collision the bowling ball has a velocity of 2 m/s and the tennis ball is at rest. After the collision the bowling ball is at rest and the tennis ball has a velocity of 14 m/s. Was momentum conserved during the collision?
yes
AgNO^3 + NaCl ----> AgCl + NaNO^3
yes
C^4H^8 + 6 O^2 ----> 4 CO^2 + 4 H^2O
yes
net force
The overall force acting on an object after all the forces are combined
pulley
a simple machine that consists of a rope that fits into a groove in a wheel
inclined plane
a slanted surface along which a force moves an object to a different elevation.
air resistance force
a special type of frictional force that acts upon objects as they travel through the air
what is a constant acceleration
a steady change in velocity
wheel and axle
a type of simple machine consisting of two disks or cylinders with different radii.
electron cloud
a visual model of the most likely locations for electrons in an atom.
D-2 equation
a2 + b2 = c2
you are bumper carting and hit your friends cart
action force- the force your bumper car exerts on the other car reaction force- the force the other car exerts on your car
if you kick a wall
action force- the force your foot exerts on the wall reaction force- the force that the wall exerts on you
action force vs reaction force
action is what you do reaction is what happens because of it
lift force examples
air plane bird tennis ball spray bottle
type of fluid friction
air resistance
nuclear force examples
all matter
electrons are
always moving
watt
amount of power it takes to do something
joule
amount of work it takes to move a body
gravitational force
an attractive force that acts between any two masses
what does the 1st law say
an object wont move unless the net force is unbalanced
kilometers per second
km/s
zero displacement
lap around a track
use kilometers for
large distances
mechanical energy examples
leaf falling riding down a hill
applied force example
leaning on a wall
where can displacement 2-D go
left to right up and down
distance
length of the path between two points
simple machines
lever wheel and axle inclined plane wedge screw pulley
law of conservation of energy example
light bulb playing pool
a fluid can be a __________ or a ___________
liquid gas
inclined plane examples
loading ramp steep road
distance can be
lots of turns
distance si unit
m
mass abreviatoin
m
meter
m
A wagon is pushed with a net force of 300 N and it accelerates at a rate of 1.5 m/s2. Calculate the mass of the wagon.
m = 200 kg
A wagon is pushed with a net force of 300 N and it accelerates at a rate of 1.5 m/s2. Calculate the mass of the wagon.
m = 200kg
A rocket blasts off with a net force of 2,000,000 N and an acceleration of 50 m/s2. Calculate the mass of the rocket.
m = 40,000 kg
A train car has a momentum of 40,000 kg· m/s and is traveling at a velocity of 8.5 m/s. Calculate the train's mass.
m = 4705.9 kg
A 25-N force accelerates a boy in a wheelchair at 0.5 m/s2. What is the mass of the boy and the wheelchair?
m = 50kg
On earth (g = 9.8 m/s2), a SJA student has an average weight of 500 N. Calculate the mass of an average student.
m = 51kg
A swimmer pushes off the wall to the left with a force of -40 N and accelerates at a rate of -0.6 m/s2. Calculate the swimmer's mass.
m = 66.7 kg
A swimmer pushes off the wall to the left with a force of -40 N and accelerates at a rate of -0.6 m/s2. Calculate the swimmer's mass.
m = 66.7 m/s^2
meters per hour
m/hr
meters per minute
m/min
initial velocity si unit
m/s
meters per second
m/s
speed si unit
m/s
velocity si unit
m/s
speed stuff
m/s number and unit always positive
velocity stuff
m/s number unit and direction
SI unit for acceleration
m/s 2
acceleration si unit
m/s2
gravity SI unit
m/s2
Calculate the mass of an object on Earth (g = 9.8 m/s2) that has a weight of 200 N.
m= 20.4 kg
compound
made from two or more simpler substances, joined in a fixed proportion
1-D displacement
man walking in a line
law of conservation of mass
mass cannot be created or desroyed
what measures distance
meter
displacement si unit
meter (m)
distance si units
meters
STEM usually uses
metric units
mile thing
mi
use for meters for
mid-distances
imperial units
mile inch foot yard
minutes
min
three types of mixtures
mixture of: elements compounds compounds and elements
millimeters
mm
how is gravity different on the moon and on jupiter
moon less heavy jupiter heavier
more mass equals
more inertia
what is needed in order for force to do work
motion and force in the same direction
what do unbalanced forces do
moves or stops object
electron
negative outside
Negative slope
negative acceleration
neutrons
neutral inside
weight SI unit
newton (N)
nanometer
nm
Hg + O^2 ----> HgO
no
yes or no Cu + O^2
no
yes or no KNO^3 ----> KNO^2 + O^2
no
yes or no Mg + 2HCl --> H^2 + MgCl^2
no
yes or no H^2O^2 --> H^2 O+ O^2
no
No slope
no acceleration/constant vel.
are the 3rd laws forces cancelled out
no bc they are on different objects
A car travels at 30 m/s along a straight road for 200 seconds.
none
ball rolls in a straight line for the same speed
none
what 3 parts to displacement answer
number unit direction
parts to answer distance
number unit
time abreviation
t
a standard light bulb has a wattage of 60 W. If the work the light bulb does is 48,000 J, for what amount of time is the light bulb on
t 800s
A boat accelerates to the left at a rate -9 m/s2. During an unknown time, the boat increases its speed from -18 m/s to -45 m/s. Calculate the unknown time
t = 7s
centripetal force examples
tether ball spacecraft orbiting earth driving in a circle
what did aristotle propose
that force is required to keep an object moving at constant speed
buoyancy definition
the ability of a fluid (including a gass) to exert an upward force on an object placed in it
what is energy
the ability to do work
electric force definition
the attraction or repulsion between electrically charged objects
displacement definition
the direction and length from the starting to endpoint
what direction does an object accelerate
the direction of the net force
# of electrons is
# of protons
efficiency si unit
%
how to determine the direction of acceleratoin
- draw an arrow pointing in the direction the object's motion - draw an arrow pointing in the direction of the object's acceleration -Object is speeding up, arrow goes in the same direction as motion -Object is slowing down, arrow goes in opposite direction of motion
car moving to the right slowing down
--------> V negative <-------- A
car moving to the right speeding up
--------> V positive --------> A
a bicyclist is moving to the right at a speed of 4 m/s. She slows to a stop. Is the bicyclist's acceleration positive or negative
-------> V <------- A negative
a car is at rest begins speeding up to the right at the rate of 2 m/s2. Is the car's acceleration positive or negative
------> V ------> A positive
A rock is dropped from rest. It reaches a velocity of -50 m/s in 5 seconds. Calculate the rock's acceleration.
-10 m/s
A cheetah is initially running to the right at a speed of +30 m/s. It slows down to a speed of +4 m/s in a time of 13 seconds. Calculate the cheetah's acceleration.
-2 m/s2
a cheetah sprints 100m to the left in 20s what is the chetahs velocity in m/s
-5 m/s
what is the rate at which all objects fall
-9.8 m/s 2
if you start at one point then end at the same point the displacement is
0
A semi-truck has a mass of 36,000 kg. If it is moving with a velocity of 40 m/s, what is the semi-truck's momentum?
1440000 kg*m/s
A TRAIN TRAVELS 190 KILOMETERS IN 3.0 HOURS, AND THEN 120 KILOMETERS IN 2.0 HOURS. CF: 1,000 M = 1KM & 1HR = 3,600 S CALCULATE THE TRAIN'S AVERAGE SPEED IN M/S.
17.2 m/s
electrons in third ring
18
A CAR HAS A SPEED OF 30 M/S. IT MAINTAINS THAT SPEED FOR 6 S. CALCULATE THE DISTANCE THE CAR TRAVELLED.
180 m
electrons in first ring
2
2O^2 ????
2*2
A Great Dane has a mass of 100 kg and a momentum of 250 kg · m/s. Calculate the velocity of the dog.
2.5 m/s
A bullet train rushes through the countryside at 200 m/s and has a momentum of 600,000 kg · m/s. Calculate the train's mass.
3000 kg
electrons in fourth ring
32
A person does the same amount of work as the conveyor belt (3,200 J), but the person's power is much less (10 W). Do you think it will take a person more or less time to do this work? Check your answer.
320 seconds
A weight lifter raises a 1600-newton barbell to a height of 2.0 meters. Calculate the work the weightlifter has done on the barbell?
3200 J
A bowling ball has a mass of 7.26 kg. A super striker rolls the ball with a velocity of 6.2 m/s. Calculate the momentum of the bowling ball.
45.012 kg*m/s
how many rings on an atom
5
electrons in fifth ring
50
F1= -50N F2= 120N F= ?
70 N
one horsepower =
746 watts
if a machine requires 10.0 J of work input to operate to produce 7.5 J of work output. What is the machine's efficiency?
75%
electrons in second ring
8
Usain Bolt runs at a velocity of 10 m/s. If his momentum is 950 kg · m/s, what is his mass?
95 kg
A dog running to the right sees the dog catcher ahead and slows to a stop.
<-------- A --------> V negative
car moving to the left slowing down
<-------- V positive ---------A
A dragster starts from rest and increases its speed steadily to the right for 10 seconds.
A --------> v---------> positive
physical change
A change in the physical form of a substance, but does not change the chemical composition of the substance
chemical change
A change that impacts the chemical structure of a sample. In other words, changes a substance into a new substance.
sliding friction
A force that opposes the direction of motion of an object as it slides over a surface.
A semi-truck moving to the left suddenly slams on its brakes and comes to a stop.
A--------> V -------> positive
newtons 1st law
An object at rest stays at rest unless acted on by an unbalanced net force
Types of Forces
Applied force (wind blowing, person pushing) Gravity force Normal/supporting force Friction force Air resistance force Tension force
Why is Newton's 3rd Law in the same section as momentum?
Collisions
displacement 1-D equation
Df - Di = displacement
force of gravity
Earth's gravity acts downward toward the center of Earth.
friction force abbreviation
Ff
gravity force abreviation
Fg
normal force abreviation
Fn
tension force abbreviaton
Ft
A rock is thrown down off a cliff. Is the rock's acceleration positive or negative
I I I I V V negative
rock free falling towards earth
I V I A I I I I V V
Your pencil rolls of your desk and falls to the floor.
I V I A I I V V negative
how does work require motion
If there is no movement, no work is done
SI unit for force
N (newton)
fluid friction
Opposes the motion of an object through a fluid.
While removing snow from a driveway, a snow blower does 12,000 N of work in 300 s. Calculate the power of the snow blower.
P= 40W
A BASE jumper with a mass of 80 kg stands atop a 465 m cliff. Determine the type and sub-type of energy the BASE jumper has, and then calculate the amount of energy of this type.
Potential Graavitational pe=364.560
static friction
The friction force that acts on objects that are not moving.
rolling friction
The friction force that acts on rolling objects.
You throw a ball straight into the air with an initial velocity of 6 m/s and it comes to a stop in mid-air.
^ V I A I I I V negative
A pulley raises a stack of wood with a steadily increasing speed.
^ V ^ A I I I I positive
acceleration abbreviation
a
A crate has a mass of 30 kg and a man is pushing it to the left with a net force of -2.5 N. Calculate the crate's acceleration.
a = -0.1 m/s2
A helicopter has a mass of 14,000 kg and has a net force upward of 20,000 N. Calculate the helicopter's acceleration.
a = 1.4 m/s2
A boy pushes forward a cart of groceries with a total mass of 40.0 kg. What is the acceleration of the cart if the net force on the cart is 60.0 N?
a = 1.5m/s2
A rock has a mass of 0.5 kg and a river is exerting a net force of 16 N on it. Calculate the rock's acceleration.
a = 32m/s2
An automobile with a mass of 1000 kilograms accelerates when the traffic light turns green. If the net force on the car is 4000 newtons, what is the car's acceleration?
a = 4 m/s2
acceleration equation
a = Vf - Vi/t
newtons second law formula
a = f / m
wedge
a V-shaped object whose sides are two inclined planes sloped toward each other.
compound machines
a combination of two or more simple machines that operate together
what is a machine
a device that changes a force
Force and Motion
a force can cause a resting object to move, or it can accelerate a moving object by changing the object's speed or direction
Applied Force
a force that is applied to an object by a person or another object.
friction force
a force that opposes the motion of objects that they touch as they move past each other
Friction
a force that opposes the motion of objects that touch as they move past each other.
which requires more power : mowing the lawn with a lawnmower or cutting the grass with scissors
a lawnmower because it is the same amount of work in a quicker time
force
a push or pull that acts on an object
chemical equation
a representation of a chemical reaction in which the reactants and products are expressed as formulas.
lever
a rigid bar that is free to move around a fixed point, called a fulcrum.
Sariah's 0.04-kg pencil falls from her desk. When the pencil has fallen 0.25 m, it is moving with a velocity of 2.45 m/s. Determine the type(s) and sub-type of energy the pencil has as it is falling, then calculate the amount of each type of energy.
both mechanical pe= 0.098
similarities between d t graph and v t graph
both constant and positive x is time on both they both have velocity in a way
displacement is always
both directions
Which has more momentum, a 0.046-kg golf ball with a speed of 60.0 m/s, or a 7.0-kg bowling ball with a speed of 6.0 m/s?
bowling ball
2-D displacement
boy walking home
bread becomes toast
c
digesting food
c
frying an egg
c
lighting a match
c
lighting gasoline
c
milk going sour
c
tarnished silver
c
how to determine instantaneous velocity/ speed
calculate the slope between given points positive slope= positive velocity negative slope = negative velocity
what did newton invent
calculus
chemical energy examples
car burning gas drinking 5hr energy
example of changing force
car jack: little push down is a big push up on car
example of change in direction
carousel
types of acceleration
change in: speed direction speed and direction
what 3 things does a machine do
change the size of a force needed the direction of a force the distance over which the force acts
centimeters thing
cm
centimeters per minute
cm/min
centimeters per second
cm/s
types of chemical changes
color product of gas (bubbles) combustion or burning
example of slowing down
coming to a stop in a car
mixture
composition is not fixed, properties may vary
normal force example
computer on desk
distance abreviation
d
symbol for distance
d
A bus starts at 5 m and moves to -60 m. What is the bus's distance and displacement?
d = 65 m
A snail starts moving at 0 m and stops moving at 75 m. What is the snail's distance and displacement?
d = 75 m
when there are multiple distances in a 1-D problem
d= d1 + d2 + d3.......
when there are two distances in a 2-D problem
d= d1 +d2
when there is one distance in a 1-D problem
d= d1 = delta d
what is the thing for displacement
delta (triangle) d
snail starts at 0 m and stops at 75 m what is the d and delta d
delta d = +75m d = 75 m
if i start at 50m then go to 15m then to 35m then finish at -5m what is the delta d and the d
delta d = -55m d = 95m
equation for 2-D problems or triangle problems
delta d = c a2 + b2= c2
equation for 1-D problems or number line problems
delta d = df - di
bus starts at 5 m and goes to -60 m what is the d and delta d
delta d= -65m d = 65m
how to tell the difference between p and c change
did it form a new substace
acceleration always has a
direction
distance has no
direction
kids on a mary-go-round
direction
work depends on
direction
A marching band marches 9 meters to the south and then marches 6 meters to the west. Calculate the marching band's displacement and total distance.
disp= 10.8 m SW dis = 15m
gravity goes
down
negative acceleration
down left
always ___ for displacement
draw a picture
way to remember axis
dry mix
efficiency abbreviation
eff
efficiency equation
eff = Wo/Wi * 100
A person inputs 1,000 J of work into a machine, the machine's work output is only 630 J. Calculate the machine's efficiency.
eff= 63%
gravitational potential energy
energy an object possesses because of its position in a gravitational field.
law of conservation of energy
energy cannot be created or destroyed
how are energy and work related
energy is the ability to do work
Newtons 3rd law of motion
every action has an equal but opposite reaction
how are action fores and reaction forces related
every action has an equal reaction
A ball is kicked with an unknown force to the left. The ball has a mass of 1 kg and is accelerating to the left at -4.5 m/s2. Calculate the net force on the ball.
f = -4.5 N
A plant is at rest and has a mass of 45 kg. Calculate the net force acting on the plant.
f = 0 N
A plant is at rest and has a mass of 45 kg. Calculate the net force acting on the plant.
f = 0N
An automobile with a mass of 1200 kg accelerates at a rate of 3.0 m/s2 in the forward direction. What is the net force acting on the automobile?
f = 3600N
A car has a mass of 15,000 kg and it accelerates at a rate of 3 m/s2 from a man pushing it. Calculate the net force on the car.
f= 45,00N
A man holds a box that weighs 15,00N stationary above his head for 30 seconds. The work done on the box 450,000 J True or False
false
Df
final end point
friction is the opp of what
force
what causes motion in work
force
work needs
force and motion
centripetal force definition
force continuously changes the direction of an object to make it move in a circle
Newton
force that causes a 1-kilogram mass to accelerate at a rate of 1 meter per second each second (1 m/s2 )
balanced forces
forces that combine to produce a net force of zero.
example of constant acceleration
free fall
why is the efficiency never 100%
friction
foot thing
ft
gravity abbreviation
g
The astronaut's mass of 112 kilograms does not change, but now her weight is 2,500 N? Calculate the acceleration due to gravity
g = 22.3 m/s2
An object has a mass of 6 kg and on Jupiter is has a weight of 147 N. Calculate the acceleration due to gravity on Jupiter.
g = 24.5 m/s2
An object has a mass of 100 kg and on Mars has a weight of 370 N. Calculate the acceleration due to gravity on Mars.
g = 37 m/s2
electric force examples
going down a slide combing your hair lightning rubbing your socks on the floor
what are the two types of potential energy
gravitational and elastic
example of inertia 2
hitting the bottom of the pool with your head your skull stops but the brain keeps going
potential energy (gravity) examples
holding a phone rock on a cliff
what does nuclear energy do
holds the nucleus of an atom together
what did galileo study
how gravity produces constant acceleration
horsepower abbreviation
hp
hours
hr
secret to check
if the arrow is negative then negative displacement if the arrow is positive then positive displancement
inch thing
in
acceleration on an object is
in the direction of the net force
how do you increase power
increase amount of work
reducing friction.....
increases efficiency
car driving down road increasing speed
increases speed
how does newtons first law relate to inerita
inertia says that an object at motion will stay in motion and an object at rest will stay at rest unless acted upon by another force. this is the first law
Di
initial start point
unbalanced force
is a force that results when the net force acting on an object is not equal to zero
screw
is an inclined plane wrapped around a cylinder.
matter
is anything that has mass and takes up space
potential energy
is energy that is stored as a result of position or shape
terminal velocity
is the constant velocity of a falling object when the force of air resistance equals the force of gravity.
mass
is the measure of the amount of material an object contains
power
is the rate of doing work
inertia
is the tendency of an object to resist a change in its motion
when there is one distance id a d1 problem
it equals the displacement
when you kick a ball with a momentum of 4 the ball then has the same momentum
it is conserved
energy si unit
joule
kinetic energy abbreviation
ke
kinetic energy formula
ke = 1/2 mv^2
a 0.10 kilogram bird is flying at a constant speed of 8 m/s. What is the bird's kinetic energy?
ke= 3.2 J
what do balanced force do
keeps an object at rest
kilogram
kg
mass SI unit
kg
momentum si unit
kg*m/s
what measures mass
kilogram
what are the metric units
kilometer centimeter millimeter nanometer
In a copper wire, copper atoms move at a speed of 3,000 m/s in order to conduct electricity. A copper atom has a mass of 0.064 kg. Determine the type and sub-type of energy a copper atom has in this scenario. Then calculate, the amount of energy of this type.
kinetic electric ke= 288,000
forms of energy
kinetic energy potential energy mechanical energy thermal energy chemical energy electrical energy nuclear energy
kilometers thing
km
kilometers per hour
km/hr
A protein bar has an unknown amount of energy within it. Shelley (m = 55 kg) eats the protein bar before her big game. During the game, she runs at an average velocity of 0.5 m/s. Assuming all of the energy from the protein bar was transferred into Shelley's kinetic energy in the big game, calculate how much energy the protein bar had. Also determine the type and sub-type of energy in the protein bar.
potential chemical ke- 6.9J
An atomic bomb utilizes radioactive atoms undergoing fission to wreak destruction. However, before the atomic bomb explodes it has A LOT of energy within it. Determine the type and sub-type of energy. You do not need to perform a calculation.
potential nuclear
mechanical energy is the sum of what
potential energy kinetic energy
doing work fast requires more
power
power equation
power = work/ time
how are work and power related
power is the work done in a certain time
parts of an atom
proton neutron electron
example of direction of force
pulley: pulling down pulls the object up
two parts of a chemical equation
reaction product
how to calculate slope
rise over run
thrust force examples
rocket plane swimming
example of change in speed and direction
roller coaster
kinetic energy examples
running throwing a ball
example of inertia 1
running then stopping your feet stop but your body goes forward
seconds
s
speed abbreviation is
s
time si unit
s
During a car chase, a police officer pursues a suspect at a constant speed of 50 m/s along a straight road. The suspect steadily gets further away from the police officer. Answer for both the police officer and suspect.
s- speeding up p- none
speed equation
s= d/t
compound machine examples
scissors cars washing machines clocks
screw examples
screw water bottle wine opener
lever examples
seesaw crowbar screwdriver taking of paint lids
types of physical change
shape mixing two substances phase change (ice melting) property change
neutrons mass is ___________ to a protons
similar
gravity force example
sky diving
friction force example
sliding a book on a desk
what does air resistance do
slow down
bus is coming to a stop
slowing down
fluid friction does what to an object
slows it down
us centimeters or millimeters for
small distances
electrons are _______ then protons
smaller
mass is in what forms
solids liquids and gases
steeper the slope the higher the
speed
slope is
speed or velocity
what does gravity do
speed up
types of change in speed
speeding up slowing down
what is the most force to least
static sliding rolling
sliding friction is less than....
static friction
4 main types of friction
static friction, sliding friction, rolling friction, and fluid friction.
wheel and axle examples
steering wheel screw driver
displacement
straight line from one point to another
potential energy (elastic) examples
stretching rubber band pulling leggings
element
substance that contains only one type of atom, cannot be broken into simpler substances
Car #1 has a mass of 5,000 kg and Car #2 has a mass of 10,000 kg. Before a collision Car #1 has a velocity of 2 m/s and Car #2 is at rest. After the collision, Car #1 is at rest and Car #2 has a velocity of 1 m/s. Was momentum conserved during the collision?
yes
yes or no 2 C^2H^2 + 5 O^2 -----> 4 CO^2 + 2 H^2O
yes
yes or no 2 K + 2 H^2O -----> 2 KOH + H^2
yes
yes or no 2Na + Cl^2 --> 2NaCl
yes
yes or no C^2H^4 + 3O^3 --> 2CO^2 + 2 H^2O
yes
yes or no HCl + NaOH ----> H^2O + NaCl
yes
The Joker ride at Six Flags rocks back and forth. It comes to a stop at its high point and then swings back down.
yes all
A horse sprints around a circular track at a constant speed of 3.5 m/s.
yes change in direction
A pitcher releases a softball with an initial speed of 40 m/s. When the catcher catches the ball, its speed it 0 m/s.
yes slow down
A dragster starts from rest and increases its speed steadily for 10 seconds.
yes speed up
buoyancy examples
you float more in the ocean more then a pool you can lift more in a pool boats in water balloon filled with helium will float better that with air
in order to have a large momentum
you need a large product of mass and velocity
on the moon and in space......
your mass is the same
the momentum for an object at rest is
zero
