Answer:
a. wavelength of the sound, 
b. observed frequecy, 
Given:
speed of sound source,
= 80 m/s
speed of sound in air or vacuum,
= 343 m/s
speed of sound observed,
= 0 m/s
Solution:
From the relation:
v =
(1)
where
v = velocity of sound
= observed frequency of sound
= wavelength
(a) The wavelength of the sound between source and the listener is given by:
(2)
(b) The observed frequency is given by:


(3)
Using eqn (2) and (3):


Well Inertia means something wants to stay in place, and in reality that coin wants to stay in one place, If you placed it on an index card on a cup, and SLOWLY pulled it, it wouldn't be fast enough to overcome that force, if you pulled it quickly that coin would stay in place and drop into the cup.
Answer:
A. The bird watcher followed the south trail a distance of five kilometers in 45 minutes.
The mechanical advantage of a machine is the ratio of the force produced by the machine to the force applied to it. Therefore, we may calculate the applied force using:
Mechanical advantage = force by machine / force applied
6 = 2 / force applied
Force applied = 1/3
Thus, the distance that the effort must move will be 1/3 inch
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