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):
Answer:
s = 0.9689 m
Explanation:
given,
Height of fall of paratroopers = 362 m
speed of impact = 52 m/s
mass of paratrooper = 86 Kg
From from snow on him = 1.2 ✕ 10⁵ N
now using formula
F = m a
a = F/m
Using equation of motion
v² = u² + 2 a s
s = 0.9689 m
The minimum depth of snow that would have stooped him is s = 0.9689 m
-- In order to achieve constant verlocity, the net force on the mass must be zero. So if there ARE any forces acting on it, they must be balanced.
-- There is already a force on the mass that can't be eliminated . . . the force of gravity.
-- That force due to gravity is (mass x gravity) = (25 kg)(9.8 m/s²) = <em><u>245N</u></em> in the <u><em>downward</em></u> direction.
-- In order to 'balance' the forces and make them add up to zero, we have to provide another force of <em>245N</em>, all in the <em>upward</em> direction.
-- Then the forces on the object will be balanced, the NET force on it will be zero, and whichever way you start it moving, it will continue to move at a cornstant verlocity.
