Residents of Hawaii are warned of the approach of a tsunami by sirens mounted on the tops of towers. Suppose a siren produces a sound that has an intensity level of 120 dB at a distance of 2.0 m. Treating the siren as a point source of sound, and ignoring reflections and absorption, find the intensity level heard by an observer at a distance of (a) 12 m and (b) 21 m from the siren. (c) How far away can the siren be heard?
Residents of Hawaii are warned of the approach of a tsunami by sirens mounted on the tops of towers. Suppose a siren produces a sound that has an intensity level of 120 dB at a distance of 2.0 m. Treating the siren as a point source of sound, and ignoring reflections and absorption, find the intensity level heard by an observer at a distance of (a) 12 m and (b) 21 m from the siren. (c) How far away can the siren be heard?
Residents of Hawaii are warned of the approach of a tsunami by sirens mounted on the tops of towers. Suppose a siren produces a sound that has an intensity level of 120 dB at a distance of 2.0 m. Treating the siren as a point source of sound, and ignoring reflections and absorption, find the intensity level heard by an observer at a distance of (a) 12 m and (b) 21 m from the siren. (c) How far away can the siren be heard?
43. A mass må undergoes circular
motion of radius R on a hori-
zontal frictionless table, con-
nected by a massless string
through a hole in the table to
a second mass m² (Fig. 5.33).
If m₂ is stationary, find expres-
sions for (a) the string tension
and (b) the period of the circu-
lar motion.
m2
R
m₁
FIGURE 5.33 Problem 43
CH
70. A block is projected up an incline at angle 0. It returns to its initial
position with half its initial speed. Show that the coefficient of ki-
netic friction is μk = tano.
Passage Problems
A spiral is an ice-skating position in which the skater glides on one
foot with the other foot held above hip level. It's a required element
in women's singles figure-skating competition and is related to the
arabesque performed in ballet. Figure 5.40 shows Canadian skater
Kaetlyn Osmond executing a spiral during her medal-winning perfor-
mance at the 2018 Winter Olympics in Gangneung, South Korea.
77. From the photo, you can conclude
that the skater is
a. executing a turn to her left.
b. executing a turn to her right.
c. moving in a straight line out of
the page.
78. The net force on the skater
a. points to her left.
b. points to her right.
c. is zero.
79. If the skater were to execute the same
maneuver but at higher speed, the tilt
evident in the photo would be
a. less.
b. greater.
c. unchanged.
FIGURE 5.40 Passage
Problems 77-80
80. The tilt angle 0 that the skater's body
makes with the vertical is given ap-
proximately by 0 = tan¯¹(0.5). From this you can conclude…
Human Physiology: An Integrated Approach (8th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.