FACULTY OF SCIENCE, AUTUMN 2007
PHYS 124 LEC A1 : Particles and Waves (Instructor: Marc de Montigny)
Walker, Physics, Chapter 2: One-Dimensional Kinematics
- Section 2.1: Position, Distance, Displacement
- distance = total length of travel (not negative, no direction associated with it)
- displacement Δx = final position xf - initial position xi (any sign is possible, it is a vector)
- P. 19, Active Example 2-1, by using Figure 2-2.
- Section 2.2: Average Speed and Velocity
- Average speed: p. 19, Eq. (2-2)
- Average velocity: p. 21, Eq. (2-3)
- Speed is to distance what velocity is to displacement
- Section 2.3: Instanteneous Velocity
- Definition in p. 23, Eq. (2-4)
- Section 2.4: Acceleration
- Average acceleration: p. 25, Eq. (2-5) and
- Instanteneous acceleration: p. 26, Eq. (2-6).
- Section 2.5: Motion with Constant Acceleration
- average acceleration = instanteneous acceleration
- P. 30, Eq. (2-7) follows from definition of constant acceleration
- P. 31, Eq. (2-9) is proved at the very top of p. 31. Not so useful in practice for us.
- P. 31, Eq. (2-10) follows from Eqs. (2-8) and (2-9)
- P. 32, Eq. (2-11) will be quite useful. It is obtained in p. 32.
- see p. 34, Table 2-4 Constant-Acceleration Equations of Motion
- Examples will be discussed in next two sections
- To slow down means that the speed (i.e. absolute value of the velocity) decreases. In other words, this is when velocity and acceleration have different signs. More details in Walker, pp 28-29.
- Section 2.6: Applications and Equations of Motion
- P. 51, Problem 61 [answer: (a) 5.20 m, (b) 2.60 m, (c) 2.60 m/s]
- Section 2.7: Freely Falling Objects
- Special case of Equations of Motion with a = -g (if x is chosen positive upwards, g = 9.81 m/s2)
- P. 53, Problems 99 [answer: 3.01 m ] and 100 [answer: 9.00 m/s]. (Detailed calculations for no 100)