It's actually Friction.
I just did the test and got it right.
Answer:
120 m
Explanation:
Given:
wavelength 'λ' = 2.4m
pulse width 'τ'= 100T ('T' is the time of one oscillation)
The below inequality express the range of distances to an object that radar can detect
τc/2 < x < Tc/2 ---->eq(1)
Where, τc/2 is the shortest distance
First we'll calculate Frequency 'f' in order to determine time of one oscillation 'T'
f = c/λ (c= speed of light i.e 3 x
m/s)
f= 3 x
/ 2.4
f=1.25 x
hz.
As, T= 1/f
time of one oscillation T= 1/1.25 x
T= 8 x
s
It was given that pulse width 'τ'= 100T
τ= 100 x 8 x
=> 800 x
s
From eq(1), we can conclude that the shortest distance to an object that this radar can detect:
= τc/2 => (800 x
x 3 x
)/2
=120m
Given the following in the problem:
Distances : 2.0 m and 4.0 m
Sound waves : 1700 hz
Speed of sound : 340 m/s
Get the wavelength of the sound by using the formula:
Lambda = speed of sound/sound waves
Lambda = 340 m/s / 1700 hz
Lambda = 0.2
Get the path length difference to the point from the two speakers
L1 = 4mL2 = sqrt (42+ 22) m
Delta = 4.47
x = delta / lambda
If the outcome is nearly an integer, the waves strengthen at the point. If it is nearly an integer +0.5 the waves interfere destructively at the point. If it is neither the point is somewhat in in the middle.
Solving x = (4.47 – 4) / (0.2) = 2.35 an integer +0.5 so it’s a point of destructive interference.
Answer:
Δ L = 2.57 x 10⁻⁵ m
Explanation:
given,
cross sectional area = 1.6 m²
Mass of column = 26600 Kg
Elastic modulus, E = 5 x 10¹⁰ N/m²
height = 7.9 m
Weight of the column = 26600 x 9.8
= 260680 N
we know,
Young's modulus=
stress = 
= 
= 162925
strain = 
now,



Δ L = 2.57 x 10⁻⁵ m
The column is shortened by Δ L = 2.57 x 10⁻⁵ m
It would be rock by erosion bc the rocks erode to form a volcano