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What is Science?
Motion
momentum and energy
gravity
heat
100
How is a Law in science different than a Theory?
Laws are scientific hypotheses that have been tested over and over and never been contradicted. A Scientific Theory is a synthesis of a large body of information including facts and laws. Theories are overarching groups of ideas that help explain big ideas in science.
100
What equation shows the relationship between speed, distance and time? How are speed and velocity related?
Speed = distance / travel time Velocity = speed + direction of travel
100
write the equation for momentum and describe what level of mass and velocity produce the lowest momentum and the highest momentum? Name an animal that moves with an extremely low momentum and one that can achieve extremely high momentum by using the relationship between mass and velocity stated above.
Momentum = mv Low mass and low velocity - lowest momentum - beetle High Mass and High Velocity - highest momentum - Whale or charging Wildebeast.
100
what is the acceleration due to gravity at the surface of the Earth?
9.8 m/s^2
100
How are heat and temperature related?
Heat is the thermal energy transferred from a warmer thing to a cooler thing. Temperature is a measure of the kinetic energy of particles in a thing.
200
What are two main factors that cause the seasons?
Tilt of Earth and length of daylight hours.
200
What are the controls of a motorcycle that can change it's velocity?
accelerator, brake lever and handlebars.
200
DAILY DOUBLE!!!! Suppose I somehow ended up on a skateboard with negligible friction and wanted to move without putting my foot down and pushing off. I am not carrying anything. How could I move?
To move, I'd have to take off clothing and throw in the opposite direction on where I wanted to move. Or take deep breathes and exhale forcefully... Momentum
200
According to the equation for gravity, a.) what happens to the force between two bodies if the mass of only one body is doubled? b.) Masses of both bodies are doubled?
a.) If one mass is doubled, then the force is doubled. b.) If both are doubled then the force is four times as much. example: Initial problem Force ~ (M1 X M2) / d^2 so if M1 = 10kg, M2 = 10kg and d = 5 meters F ~ 100kg / 25m^2 = 4N a.) double one mass if M1 is 20kg F ~ 200kg / 25m^2 = 8N (force is doubled) b.) double both masses if M1 and M2 are 20 kg (doubled) F~ 400 kg / 25 m^2 = 16N (force is quadrupled)
200
What is entropy? Give an example
The measure of energy from highly organized states to more disorganised and diffuse states. The dispersal of energy over time. a candle flame, an open perfume bottle, a rotting tree...
300
What are 2 main characteristics of science?
It is guided by questions that relate to natural phenomena It has to be explanatory by reference to natural law It is testable against the empirical world (it is falsifiable) Its conclusions are tentative (never proven) It demands evidence It is a blend of logic and imagination It Explains and predicts Scientists try to identify and avoid biases
300
What property of a moving object would we measure to see if it is or is not in equilibrium?
we would measure it's velocity. If it's velocity is not changing then it is in equilibrium.
300
Define "work" in science and solve the following: How much work is required to lift an object that weighs 500N to a height of 4 m? How about an object with a mass of 100kg?
Work is the product of the amount of force (Newtons) X distance and is measured in Joules. Problem a. w = F X d = 500N X 4m = 2000J Problem b. 1kg = 9.8N (round to 10N) 100kg = 1000N w = F X m = 1000N X 4m = 4000J
300
Do astronauts orbiting Earth in the international space station experience gravity? Explain.
They do not experience gravity because they are in free fall - the space station and everything in it are traveling towards earth at the same speed, so there is no support force to make you feel weight. Gravity is causing the downward acceleration of the space station, but the people inside it do not feel it's effects because they are falling at the same rate.
300
Define three forms of heat transfer with examples.
Conduction - transfer of thermal energy through collisions within solid materials. (Cold metal flagpole and tongue) Convection - transfer of thermal energy in liquid or gas through flow of fluid. (sea breeze vs land breeze) Radiation - transfer of thermal energy through electromagnetic waves (solar panels)
400
Define Pseudoscience and give an example
Claims made about the natural world that do not meet the standards for science. (these standards are: Must be reproducible, must be testable, must be able to be scrutinized and results must be openly shared) EXAMPLES: ASTROLOGY, UNTESTED NATURAL REMEDIES,
400
A ball starting from rest falls from the top of a building and hits the ground in 5 seconds. 

[a] How fast is the ball going when it hits the ground? 
[b] How tall is the building?
a. v = at where a = g v = 9.8 m/s^2 X 5sec v = ~50 m / s b. d = (1/2) at^2 d = (1/2) [9.8 m/s^2 X 5^2sec] d = (1/2) [9.8 m/s^2 X 25s^2] d= (1/2) ~250 m d = 125m
400
Does a moving soccer ball in the air possess energy? Force?
Yes, the ball does possess KE, relative to the Earths energy, and PE in relation to it's height over the ground. It does not possess force however, since force is a property that acts on objects. The force of gravity is acting on the ball, as is the force of air friction and the force your foot applied to it initially.
400
Why are women often more stable ( in terms of balance and the ability to lift objects while bent over) then Men?
Their center of gravity is often lower, giving them a greater support base.
400
How do the oceans cause wind?
they heat and cool more slowly than the land on the continents, creating unequal air temperatures in wide regions of the Earth, and then through convection currents, wind.
500
What is a paradigm shift in science?
A new assumptions about a theory or idea in science that requires the reconstruction of prior assumptions and the reevaluation of prior facts (difficult and time consuming) It is strongly resisted by the established community When a shift takes place, “a scientist's world is qualitatively transformed [and] quantitatively enriched by fundamental novelties of either fact or theory”
500
What net force does a broken down truck experience if you exert a force of 125N while pushing it to the mechanics garage, and the friction of the gravel road on the tires exerts a force of 125N? How long will it take to get to the mechanics shop?
the truck experiences a net force of 0. It is at equilibrium and doesn't move.
500
What is power? How much power is needed to lift a 5000N piano up to your second floor apartment (10m) in a time of 5 sec?
Power is a measure of how quickly work is done or the rate at which energy is changed from one form to another. power = work done/time Problem: power = work*/time * remember that work done = force X distance...so power needed = 5000N X 10 m / 5 sec = 50000J / 5 Sec = 10000 W or 10kW.
500
Why don't planets crash into the sun?
Because, their tangential velocity is great enough to escape the gravitational pull of the sun. They travel in parallel to the surface of the Sun, constantly falling towards it's core, but travelling fast enough to avoid being pulled to it.
500
Describe 3 laws of thermodynamics
1. Thermal energy transfer takes place with no net loss or gain to the system. The energy lost in one place is gained in another. You don't get thermal energy from nothing. 2. Heat never spontaneously flows from a lower temperature substance to a higher temperature substance. 3. No system can reach absolute zero.