Semester 2 Science Finals Flashcards
Sublimation
The change of state from a solid directly to a gas. Must gain energy.
Transpiration
The process by which plants release water vapor into the air through a leaf or stem. Must gain energy.
Evaporation
The change of state from a liquid to a gas that usually occurs at the surface of a liquid over a wide range of temperature.
Condensation
The change of state from a gas to a liquid.
Deposition
The change of state from a gas to a solid.
Precipitation
Water that falls to the ground (rain, snow, hail, sleet).
Run-off
Precipitation that flows over the land and into streams and rivers.
Infiltration
Water seeping below Earth’s surface into space in soil and rock.
Saturated
When something can’t hold anymore water.
What drives the water cycle?
Sunlight and gravity.
Changes: Gains Energy
Solid to liquid
Liquid to Gas
Solid to Gas
Changes: Loses Energy
Gas to liquid
Liquid to Solid
Gas to Solid
Physics
The study of how things move (motion) and why things move (forces)
Force
A push or pull exerted on an object
Motion
The state in which one object’s distance from another is changing.
Speed
The rate of change of position of matter. distance over time.
Velocity
Speed with direction which makes velocity a vector quality (size and direction). Not just numbers. Displacement over time.
Acceleration
A change in velocity over a period of time (increase, decrease, change direction). a=Vf-Vi/t
Distance
A scalar quantity that describes “how much ground” an object has covered during its motion.
Scalar Quantities
Describe matter using magnitude (size) and units of measurement.
Displacement
A vector quality that describes “how far away from the start” an object is during the object’s motion.
Distance-Time
Shows distance. Cannot time travel or lose distance.
Position-Time
Cannot time travel - can “lose” distance (displacement). Shows displacement or “position” over time. Can find velocity from PT slope.
Velocity-Time
Shows the velocity over time (for each interval). Slope = acceleration.
Acceleration Graph
Shows the acceleration over time. Always a straight line.
Gravity
A force of attraction between objects due to their masses. Non contact force. Attraction force because it always pulls objects together. Gravity is weak. The farther the distance between masses - the weaker the gravitational pull.
What do all forces have?
Strength and direction.
What can forces change of an object’s motion?
Speed or direction.
What are forces measured in? Equation for this.
Newtons. 1N=1kg x (m/s^2)
What do Free Body diagrams do?
- Explain all forces acting on an object
- Shows NET force
What makes a system stable?
If the forces acting on the object aren’t changing the motion or state of the object. (can move at a constant rate = stable)
Contact Forces and Example
Only act on objects that are touching (ex. friction).
Non Contact Forces and Example
A force that can act at a distance. (magnets and gravity).
Friction
The force that opposes motion between any objects in contact.
What two factors affect friction?
Surface type and the amount of force between objects
Friction acts in a direction _______ to an object’s motion
Opposite
What are the four types of friction?
Static, sliding, rolling, fluid.
Static Friction
Occurs between objects that aren’t moving. Without static friction, your feet would slip out from under you, making it difficult to walk. Ice is very slippery because it has very little friction.
Sliding Friction
Occurs when two solid surfaces slide over each other. It makes moving objects slow down and stop. Weaker than static friction.
Rolling Friction
When an object rolls along a surface. Much weaker than static or sliding friction. Though wheels are great fir rolling and reducing friction, they wouldn’t work without static friction.
Fluid Friction
When a solid object moves through a fluid. Easier to overcome than sliding friction. Air resistance is fluid friction. A fluid is a substance that can flow and take on the shape of its container (liquid or gas).
Newton’s First Law
Unless acted on by an unbalanced force, an object at rest stays at rest and at object in motion stays in motion at a constant velocity. It’s sometimes called the law of inertia. Inertia is the tendency of objects to resist any change in motion. More mass = more inertia.
Momentum
The product of the object’s mass and the object’s velocity.