Nature of Science
Something you can see, taste, touch, hear or smell.
Observation
The factor that a scientist purposely changes during an experiment.
Independent Variable
A force is simply a _____ or a _____.
Push or Pull
When forces are equal in size and opposite in direction, they are called....
Balanced Forces
Motion happens when an object's _____ changes compared with a reference point.
Position
You see dark clouds and say, “It is probably going to rain.” The statement about rain is this: an observation or an inference?
Inference
The factor that is measured or observed as a result of the change.
Dependent Variable
Which object would experience the greatest force of gravity- a baseball, a pen, or a desk?
The desk, since it has the most mass.
Two students push a box in opposite directions with 20 N each. What is the net force?
0 N of net force
A student travels 20 meters in 4 seconds. What is their speed?
5 meters per second (m/s)
This is a well-supported explanation for HOW or WHY something happens in nature.
Scientific Theory
A student tests whether the amount of sunlight affects plant growth. What is the independent variable?
Amount of Sunlight
Friction usually acts in this direction compared with an object's motion.
Opposite the direction of motion
A box is pushed 15 N right and 5 N left. What is the net force AND direction?
10 N to the right
On a distance-time graph, what does a steeper slope tell you about an object's speed?
That object is going faster
This describes a pattern or relationship that consistently happens in nature, but does not explain WHY it happens.
Scientific Law
Three plants receive different amounts of sunlight, but all receive the same amount of water and use the same type of soil. Water and soil are examples of these.
Constants
Gravity, magnetism, and electric force belong to this category because objects don't have to touch for the force to act.
Non-contact Forces
Look at the drawing A on the board- what is the net force?
50 N to the right
Look at graph A on the board- describe what is happening at each line segment, between point A and B, between point B and C, and between point C and D? Include if it's constant or not, and compare which lines are faster.
The speed is constant and distance is increasing from A to B, 0 speed or distance between B and C, and even faster and constant between C and D.
TRUE or FALSE: When scientists collect enough evidence, a scientific theory can eventually become a scientific law.
False- False. Theories and laws have different purposes; theories do not “graduate” into laws.
A student wants to know whether fertilizer affects plant growth. Plant A gets fertilizer and Plant B gets no fertilizer. What would plant B be called? Why is Plant B important?
It is the control/control group and provides something to compare the experimental results to.
A skydiver is falling downward. Name TWO forces acting on the skydiver and their directions.
Gravity pulling them downward, air resistance pulling them upward.
Look at Drawing B on the board, what is the net force?
35 n to the left
Describe what is happening between points A and B, B and C, and C and D. Include if it's constant or accelerating or decelerating.
It's accelerating between A and B, Constant increase between B and C, and Decelerating between C and D.