8.9 Investigation and Experimentation

Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept, and to address the content the other three strands, students should develop their own questions and perform investigations. Students will:

- Plan and conduct a scientific investigation to test a hypothesis.
- Evaluate the accuracy and reproducibility of data.
- Distinguish between variable and controlled parameters in a test.
- Recognize the slope of the linear graph as the constant in the relationship y=kx and apply this to interpret graphs constructed from data.
- Construct appropriate graphs from data and develop quantitative statements about the relationships between variables.
- Apply simple mathematical relationships to determine one quantity given the other two (including speed = distance/time, density = mass/volume, force = pressure x area, volume=area x height).
- Distinguish between linear and non-linear relationships on a graph of data.

8.1 Motion

The velocity of an object is the rate of change of its position. As a basis for understanding this concept *Students Know* :

- position is defined in relation to some choice of a standard reference point and a set of reference directions.
- that average speed is the total distance traveled divided by the total time elapsed and that the speed of an object along the path traveled can vary.
- how to solve problems involving distance, time, and average speed.
- the velocity of an object must be described by specifying both the direction and the speed of the object.
- changes in velocity may be due to changes in speed, direction, or both.
- how to interpret graphs of position versus time and graphs ofspeed versus time for motion in a single direction.

8.2 Forces

Unbalanced forces cause changes in velocity. As a basis for understanding this concept *Students Know* :

- a force has both direction and magnitude.
- when an object is subject to two or more forces at once, the result is the cumulative effect of all the forces.
- when the forces on an object are balanced, the motion of the object does not change.
- how to identify separately the two or more forces that are acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction.
- that when the forces on an object are unbalanced, the object will change its velocity (that is, it will speed up, slow down, or change direction).
- the greater the mass of an object, the more force is needed to achieve the same rate of change in motion.
- the role of gravity in forming and maintaining the shapes of planets, stars, and the solar system.

Student effort and participation are important factors in academic success. As a basis for demonstrating effort and participation *Students Will* :

- make a consistent effort and turn in completed assignments on time.
- offer ideas and asks questions in class which makes the contents clear for others and demonstrates good group work.
- be consistently on task and focused. They listen to others and provide input.
- show respect for others and the teacher and ask questions in a respectful way.