FACULTY OF SCIENCE, AUTUMN 2007
PHYS 124 LEC A1 : Particles and Waves (Instructor: Marc de Montigny)
Walker, Physics, Chapter 4: Two-Dimensional Kinematics
- Section 4-1: Motion in Two Dimensions
- You may read pp. 80-81. The main point of this chapter is that each component (x, y, z) behaves independently from the others, each one with its own acceleration (resp. ax, ay, az)
- I will discuss the case of constant acceleration, bottom of p. 81. The relevant equation are given in p. 82, Table 4-1.
- Section 4-2: Projectile Motion
- The remaining of this Chapter (i.e. Sections 4-2,3,4,5) is simply a particular case of the equation of Table 4-1 (p. 82).
- Walker defines the y as being vertical. Therefore, the constant acceleration vector is (ax, ay) = (0,-g), where g = 9.8 m/s2. Caution: avoid the double-negatives, that is, taking both ay = -g as well as g = -9.8 m/s2.
- Equations of motion are in Eq. 4-6 of p. 83
- Section 4-3: Zero-Launch Angle
- omitted, because the next Section includes it as a particular case
- Section 4-4: General Launch Angle
- Useful equations are Eqs. 4-10 of p. 89
- These equations are obtained from Eqs. 4-6 by choosing
- x0 = 0 = y0
- v0x = v0 cosθ
- v0y = v0 sinθ
- See p. 89, Figure 4-6
- We will discuss P. 92, Example 4-6
- Section 4-5: Characteristics of Projectile Motion
- The range R (P. 93, Figure 4-8) is the total distance traveled horizontaly
- Do NOT memorize equations such as 4-12 or 4-13. Instead you should understant how to obtain these equations.
- The section Symmetry in Projectile Motion underlines various quantities which are similar on both sides of the maximum height
- The main concept of the section Maximum Height is that it is reached when vy = 0