17. Given that the speed of sound is 340 m/sec, how much time will elapse between seeing a lightning flash and hearing the resulting thunder if the lightning strikes 3.50 km away? Note: Since the speed of light is 3.00 x 108 m/sec, or about 186,000 mi/hr, the lightning flash is seen "instantaneously."
18. A plot of position versus time is shown in Fig. 2.17 for an object in linear motion.
(a) What are the average velocities for the segments AB, BC, CD, DE, EF,
FG, and BC? (b) State whether the motion is uniform or nonuniform in each
case.
(c) What is the instantaneous velocity at point D?
19. In demonstrating a dance step, a person moves in one dimension as shown in a Fig. 2.18.
(a) What is the average speed?
(b) What is the average velocity for each phase of the motion?
(c) What are the instantaneous velocities at t = 1.0 s, 2.5 s,
4.5 s, and 6.0 s?
(d) What is the average velocity for the Interval between t = 4.5
seconds and t = 9.0 seconds? [Hint: Recall that the effective
displacement is the displacement between the starting point and the ending
point.)