Projectiles

Physics A took time to discuss and practice techniques for working with non-perpendicular vectors. When vectors don't make a nice right triangle on their own, we must take a more complex approach to combining them. Remember the steps:

1. Sketch the situation, double-checking the direction of each vector.
2. Resolve each vector into x- and y-components, paying close attention to signs.
3. Sum all of the x-components and y-components for the vectors.
4. Make a right triangle with the Σx and Σy values.
5. Solve for the resultant, remembering both magnitude and direction.

I'll try and post a video for working with non-perpendicular vectors later today. We'll go over your homework problems on Thursday, so make sure you see me if you need extra help. Tomorrow - a lab on projectile motion. Physics B worked on the projectile motion lab in class today, calculating the landing point of a horizontally-launched projectile and testing how accurate was their prediction/calculation. Given a measured launch velocity and other bits of information, all groups hit their targets on the first try. Some groups got to engage in the Extension, where a target distance was set and the launch velocity had to be calculated (and then established). We'll go over projectile motion in more detail towards the end of the week, but remember our discussion at the start of class and use the following guidelines for helping you with your lab write up:

Summary of Results:

Main experiment - Given a table height of _______ and a launch velocity of _______, we predicted a landing distance of _______ and hit/failed to hit the target.

Extension - Given a target distance of _______ and a table height of ________, we predicted a launch speed of _______ and hit/failed to hit the target. Conclusion Ideas:

Conclusion Ideas:

• What is projectile motion?
• Why can we factor out air resistance for the ball bearing's motion?
• How did you make your predictions?
• What assumptions did you make?
• What information, measured or not, did you use?
• Why was v_x constant?
• Why did the trajectory of the motion look like half a parabola?

Introductory Physics reviewed their kinematics problems and we worked some extra for additional practice as a class. A 5-question quiz tomorrow will check both your ability to interpret/create graphs of motion and your skills with kinematics. Then, it is on to an introduction to how forces impact motion (covered in more detail in the next chapter).

Honors Physics reviewed their work on projectiles launched at an angle and also had a general review for tomorrow's exam. On Thursday, we move on to forces and the Newton's Laws of Motion.