Graphing, scalars, vectors, problem solving

Graphing Instructions 1. Title your graph – Position vs Time graph 2. Label your Y-axis distance (m) 3. Label your X-axis time (s) 4. Time should be in small increments 5. Distance should be in 1 meter increments 6. Plot the point for the fast ball data (use a colored pencil). Draw a best fit line and label the line fast ball. Include two points in best fit line. 7. Plot the point for the slow ball data (use a different colored pencil). Draw a best fit line and label the line fast ball. 8. Plot the point for the reverse ball data (use a different colored pencil). Draw a best fit line and label the line fast ball.

On the back of your graph respond to the question below 1. How did the slope (steepness) of the lines compare to each other? 2. Describe the direction of the ball during each of the three rolls. 3. What role do you think force and mass played in this experiment?

On the back of your graph respond to the question below 1. How did the slope (steepness) of the lines compare to each other? Visually the fast bowl, then reverse bowl, then slow bowl. The slope of line tells how fast the object is moving. Steeper = greater velocity. 2. Describe the direction of the ball during each of the three rolls. Considering the zero meter mark was the point of reference…the fast and slow bowl were moving away from the reference point. The reverse bowl was moving towards the reference point. 3. What role do you think force and mass played in this experiment? When I applied a greater force the ball went faster. If the mass of the ball increased then I would need to apply a greater force to keep the velocity of the ball the same.

 Mass is a measure of the number of atoms in an object combined with the density of those atoms.  Mass is matter  In order for mass to change the original object must be changed (chemical reaction, physical modification of its state).  Weight is a function of mass and the effect of gravity.  Weight can change based on the gravitational force.  Example: my mass on earth and the moon are the same but I weigh less on the moon than on the earth. Mass and Weight

Vector v. Scalar Quantities Vector Quantity Fully described by both magnitude (number plus units) AND direction Represented by arrows -displacement -velocity -acceleration -force Scalar Quantity Fully described by magnitude alone -distance -mass -temperature -time -speed -electrical charge

TermSymbol/VariableUnitsExample Stem of Question Distancedm 5 m How far…? Displacementdm 3 m north How far (and what direction) from start…? Speedvm/s 27 m/s How fast…? Velocity (speed w/direction) vm/s -43 m/s How fast and what direction…? (direction can be shown with + or -) Accelerationa m/s m/s 2 -What is the change in velocity? -What is the acceleration? Timets 7.3 s How long…? Initial speed or Initial velocity vivivivim/s How fast is the object moving at first? Final speed or Final velocity vfvfvfvfm/s How fast is the object moving at the end?

How to approach problem solving in Physics  Use a systematic way of analyzing a physical situation (aka a short story in Physics).

GUESS Method  Method for solving word problems  Given:  relevant information  clearly labeled symbol and units  Unknown:  Identify what the problem is asking you to solve for  clearly labeled with symbol  Equation:  Write it using only symbols  Substitution:  Substitute given information into your equation  Solve:  Solve algebraically for your unknown term

Applying GUESS to velocity Given distance and time solve for velocity.

Example: Sheldon from the ‘Bing Bang Theory’ runs 10 meters to the couch to play video games. It takes him 3 seconds to get there. Calculate Sheldon’s velocity.