Answer:
a. 3/4λ
d. 1/4λ
Explanation:
When the wavelength of the sound waves is λ and the two waves are having same frequency the waves are said to be out of phase if their phase difference is in the multiples of 
or 180°.
When the two waves are out of phase then their opposite maxima coincide at the same time resulting in the minimum amplitude of the resulting wave throughout.
- As we observe from the schematic that the a wave has sinusoidal pattern of variation and we get a maxima after each
of the distance.
- Here we have two speakers out of phase therefore on shifting one of the speakers by the odd multiples of we have the maxima or the extreme amplitudes.
So, we must place the microphone at 3/4λ and 1/4λ to pickup the loudest sound.
Answer:
r = 4.21 10⁷ m
Explanation:
Kepler's third law It is an application of Newton's second law where the forces of the gravitational force, obtaining
T² = (
) r³ (1)
in this case the period of the season is
T₁ = 93 min (60 s / 1 min) = 5580 s
r₁ = 410 + 6370 = 6780 km
r₁ = 6.780 10⁶ m
for the satellite
T₂ = 24 h (3600 s / 1h) = 86 400 s
if we substitute in equation 1
T² = K r³
K = T₁²/r₁³
K = 
K = 9.99 10⁻¹⁴ s² / m³
we can replace the satellite values
r³ = T² / K
r³ = 86400² / 9.99 10⁻¹⁴
r = ∛(7.4724 10²²)
r = 4.21 10⁷ m
this distance is from the center of the earth
Answer:
Explanation:
If I assume that the wind did not cause the plane to chage its velocity.
The plane will have a velocity of vp = (0*i + 100*j) km/h relative to ground
The cart has a velocity of vc = (0*i - 20*j) km/h relative to the plane
vc' = vc + vp
vc' = (0*i + 100*j) + (0*i - 20*j) = (0*i + 80*j) km/h relative to the ground.
If I assume that the wind move the plane:
The plane will have a velocity of vp = (-40*i + 100*j) km/h relative to ground
The cart has a velocity of vc = (0*i - 20*j) km/h relative to the plane
vc' = vc + vp
vc' = (-40*i + 100*j) + (0*i - 20*j) = (-40*i + 80*j) km/h relative to the ground.
In reality the wind would move the plane a little, not to the full speed of the wind, somewhere between these two values, but without more data it cannot be calculated.
Answer:
Option B is the correct answer.
Explanation:
Shear stress is the ratio of shear force to area.
We have
Shear stress = 3 N/mm² = 3 x 10⁶ N/m²
Area = Area of rectangle = 10 x 10⁻² x d = 0.1d
Shear force = 50000 N
Substituting
Width of beam = 16.67 cm
Option B is the correct answer.
Answer:
Explanation:
For the first ball, the moment of inertia and the kinetic energy is:
So, replacing, we get that:
At the same way, the moment of inertia and kinetic energy for second ball is:
So:
Then, 
is equal to 
, so:
Finally, solving for 
, we get:
