352 Chapter 11 Einsteins Special Theory of Relativity Copyright 2003 Nelson

Instructional Master

Frames of Reference (Car Example)LSM 11.1-1

(a)

ball stays at rest

constant velocity

v = constant a = 0

ball moves forward in van

decreasing velocity

v decreasing a < 0 (for van)

(b)

(c) (d)

ball moves backward in van

increasing velocity

v increasing a > 0 (for van)

ball moves to the left(relative to the van)

new direction ofvans velocity

v changes direction (car turns right)

Figure 2(a) The van moves with constant velocity, and the ball stays at rest relative to the vehicle. (b) The van accelerates and the ball rolls backward relative to the vehicle.(c) The van slows down, and the ball rolls forward relative to the vehicle. (d) The ball rolls to the left relative to the vehicle. In all cases the ball remains in uniform motion relative to Earth.