1. CST Physics Review

2. Distance & Displacement Distance = the length of a path between two points (not a vector) Displacement = the length and direction an object has moved from its starting point (is a vector). It is a straight line from the starting point to the ending point.

3. Speed Constant Speed– speed doesn’t change Instantaneous Speed- the speed right now Average Speed – total distance/total time Speed = Distance/Time

4. Velocity & Acceleration Speed in a given direction Velocity is a vector (has magnitude & direction) Speed is not a vector Changes in velocity may be due to speeding up, slowing down, or changing direction (this is acceleration) Acceleration = final velocity – initial velocity/Time

5. Force A push or a pull on an object Unbalanced forces cause changes in motion Balanced forces cause no change in motion The acceleration of an object depends on the mass of the object and how much force is applied to the object. F = ma (Newton’s 2 nd Law) Net force- the result when all the forces are combined. 10 N 20 N

6. Gravity Gravity is a force All objects have it The strength of gravity depends on the mass of the objects & the distance between them Gravity & inertia (a resistance to change motion) keep space objects in orbit On Earth, the acceleration due to gravity is 9.8 m/s/s

7. Friction Friction acts in the opposite direction as the object’s motion Friction slows objects down 1.Static 2.Sliding 3.Rolling 4.Fluid (air resistance)

8. Elastic Forces Compression (squeeze) Tension (stretch)

9. Newton’s Laws of Motion 1 (law of inertia)- an object at rest will stay at rest, an object in motion stays in motion, unless acted upon by an unbalanced force 2- the acceleration of an object depends on its mass and the force applied to it 3- for every action there is an equal and opposite reaction

10. Weight, Mass, & Volume Mass = amount of matter in a object Volume = amount of space an object takes up Weight= the force of gravity on an object (mass x gravity)

11. Density & Buoyant Force The amount of mass per volume (d = m/v) Buoyant force = the upward force applied to an object submerged in a fluid An object will sink if its weight is greater than the buoyant force In water, an object with a density less than 1 will float

12. Scientific Method A process to solve problems and answer questions Manipulated variable = The one thing that is changed on purpose in an experiment Responding variable = what happens as a result of the manipulated variable

13. Accuracy, Reproducibility, Precision Accuracy = How close a measurement is to the true value Reproducibility = how close a group of measurements are to each other Precision = the measure of the exactness of a measurement