Science Final

Newton’s First Law

An object tends to stay at rest unless acted upon by an unbalanced force, and an object in motion tends to stay in motion unless acted upon by an unbalanced force

Newton’s Second Law

Force = mass x acceleration, acceleration is proportional to net force and inversely proportional to mass, force and mass are directly proportional

Newton’s Third Law

Every action has an equal and opposite reaction

Balanced and unbalanced forces

FN = F1 + F2

• Fɴ=F1+F2

  • Ex: 165N -> 💟 <-28N(friction)

  • -> = positive

  • <- = negative

    • Fɴ= 165N -28N

    • Fɴ=137N

  • Ex: 120N -> 💟 -> 140N

    • Fɴ=120N + 140N

      • Fɴ= 260N

• Inputs and outputs = the sum of all forces on you

• When the net force is 0, it does not mean there is no force being applied; it just means the forces are equal

• Constant speed/rate = balanced forces

Rules for significant figures

• All digits from 1-9 are significant

• All sandwiched 0s are significant

• Leading 0s are never significant

• Ending 0s are only significant when there is a decimal point

Spark tape analysis

Distance between the dots = speed increases because of the distance/time

When distance between the dots stays the same = speed is constant

Acceleration = change in velocity/time interval

Acceleration = m/s^2

Change in velocity = velocity final - velocity initial (m/s)

Time interval = secs

Motion Graphs: Distance vs Time, Velocity vs Time

Distance vs. Time graph = velocity (m/s)

Velocity vs. Time graph = acceleration (m/s^2)

Slope is constant = velocity is increasing, acceleration is constant

Slope changes = velocity is fluctuating, acceleration also changes

FOR CALCULATING SLOPE, LOOK BACK AT THE ORIGINAL DATA FOR SIG FIGS

• Lab 18

• As the time increased, the average speed of the car going down increased

  • We put spark tape on a car and let it roll down a ramp

    • The distance between the dots on the spark tape increased as time went on

• Lab 19

• As acceleration increased, so did net force on the car

  • We tried pulling the car at different net forces using a spring scale

• Lab 20

• Every reaction has an opposite and equal reaction

  • Spring scales + rubber bands

    • 1 partner pulling on one side, causes the force to increase the same amount on both spring scales

  • Hockey Pucks

    • Same size hockey puck when it clashes into each other, same acceleration

    • Different sizesof  hockey pucks when they collide into each other, the smaller one has higher acceleration

  • Bottle and cap with Akla Seltzer

    • Cap went further distance because it has less mass

  • Skateboard

    • When one partner pushes off, both partners got pushed back the same distance

      • Could be different due to a difference in masses

 a=v/t

acceleration (m/s²)= final velocity - initial velocity (m/s)/ change in time (s)

Law of Universal Gravitationn (formula and relationships including inverse square law)

• When the distance between objects increases by x, the gravitational force decreases by 1/x^2

  • Ex: Distance doubles, and gravitational force decreases by ¼

• When the distance between objects decreases by 1/x, the gravitational force increases by x^2

  • Ex: distance decreases by 1/100, force increases by 10,000

• The gravitational force on different objects on the same planet = different and is directly proportional to mass

• Acceleration of different masses on the same planet = the same in the absence of air resistance

• On different planets, acceleration of gravity = different planets exert different acceleration of gravity depending in mass and radius, but the acceleration is the same for all objects on the same planet

• Force of gravity between two objects = the same, effect of the force may differ

  • For example, the force of gravity between us and the Earth affects us because our mass is small, but the same force does not change the Earth due to its large mass

G vs g

G = Gravitational Constant

g = acceleration of gravity 

Force of gravity vs acceleration due to gravity

Force of gravity = depends on the mass of the object, and is directly proportional to it

Acceleration of gravity is = same for all objects on the same planet

Mass vs weight

Mass = amount of particles in an object (kg)

Weight = effect of gravity on an object (N)

Projectile motion

1. Horizontal – constant speed

   1. Horizontal velocity = stays the same 

   2. Horizontal acceleration = 0

2. Vertical – free fall

   1. Vertical velocity = changes

   2. Vertical acceleration = stays the same

2. Time to reach the ground 

   1. – only depends on vertical motion 

   2. Mass does not affect its motion, because everything on Earth accelerates the same amount 

   3. No matter how fast you throw it, the time doesn't change, the distance does change (directly proportional)

   4. The time and distance will change depending on how high you throw an object (directly proportional)

1. Horizontal vs vertical formulas

1. Horizontal formulas 

   1. D=RT, use to find distance and velocity (rate)

2. Vertical formulas 

   1. h=1/2gt^2, use if you know the height or if you know the time

      1. h =  vertical height og how high something is falling from

   2. v=gt, use to find velocity
      

F = Gm₁m₂/d²,

F=force

G = gravitational constant

d=distance

 W=mg

W = weight (N)

m = mass (kg)

g = acceleration of gravity (m/s^2)

Planetary rotation vs orbital motion

Planetary rotation = planet spinning on its axis

Orbital motion = planet’s movement around the sun

Moon - general characteristics and explanation of phases

• Earth slammed into another early planet, the debris accumulated and orbited the earth, creating the moon

  • Once governed in magma, but now dry with dust and rocks

  • Has craters because there was once living things covering the craters, but with no magma, nothing moves or goes away

• Same side of the moon always faces the Earth because it rotates at the same rate, so we always see the same face of the moon

• The amount of light we see hitting the moon from Earth causes the moon phases

• If we saw the moon from the sun, it would always be full because as the moon orbits the earth, one face of the moon will always be illuminated from the sun

• We can see the moon from Earth depending on the moon stage

Phases

Waxing = light goes from right to left

Waning = light goes from left to right

Solar vs Lunar Eclipse

• Solar eclipse = When the moon casts a shadow on the Earth, blocking out our view of the sun, occurs during the day

• Lunar eclipse = When the Earth casts a shadow on the moon, blocking the view of the moon, occurs during the night

  • Also called a blood moon when it is a partial lunar eclipse

Solar system - general characteristics and formation

• Formed 4.6 billion years ago after a star exploded called a nebula, which is made up of gas and dust

• Debrie started to accumulate because of gravity and form planets and the sun

Sun = The star which other planets orbit

Planets = A celestial body that orbits a star, enough mass for gravity to overcome solid-body forces, has a nearly round shape, and has cleared its orbital path of other debris

Dwarf Planets = smaller than a planet, has not cleared its orbit

Moons = objects that orbits a planet or dwarf planet

Asteroid belt = located in between the orbits of Mars and Jupiter, contains thousands of small rocks

Kuiper Belt = Located beyond the orbit of Neptune, contains planetesimals and other small objects that are debris from the start of our solar system

Size/scale (physical and time) of the solar system and the  universe

• Big Bang = 13.8 billion years ago

• Formation of the universe = 4.6 billion years ago

Big bang, First atoms, first stars, milky way forms, sun and solar system forms, first life on earth, dinosaurs appear, humans appear

• Mercury, venus, Earth, and Mars are all close together near the sun = terrestrial and rocky planets

• Jupiter, saturn, uranus, and neptune are more far apart and farther from the sun = gas giants

• Jupiter is the largest planet