200g*1 mole/ 18g=11.1 moles There are 11.1 moles of water.
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):
It is powered by the Earth's rotation and the moon gives a little boost.
No spacecraft has been built yet that was able to absorb harmful
radiations in space, change weather conditions on Earth, or destroy
meteors and comets which might strike Earth.
We should continue to send robotic spacecrafts into space
because they help discard some myths about objects in space.
In other words, they help us learn things that we never knew before.
