Answer:
about 14.7°
Explanation:
The formula for the angle of the first minimum is ...
sin(θ) = λ/a
where θ is the angle relative to the door centerline, λ is the wavelength of the sound, and "a" is the width of the door.
The wavelength of the sound is the speed of sound divided by the frequency:
λ = (340 m/s)/(1300 Hz) ≈ 0.261538 m
Then the angle of interest is ...
θ = arcsin(0.261538/1.03) ≈ 14.7°
At an angle of about 14.7°, someone outside the room will hear no sound.
Answer:
True The grid with more slits gives more angle separation increases
True. The grating with 10 slits produces better-defined (narrower) peaks
Explanation:
Such a system can be seen as a diffraction network in this case with different number of lines per unit length, the expression for the constructive interference of a diffraction network is
d sin θ = m λ
where d is the distance between slits or lines, m the order of diffraction and λ the wavelength.
For network with 5 slits
d = 1/5 = 0.2
For the network with 10 slits
d = 1/10 = 0.1
let's calculate the separation (teat) for each one
θ = sin⁻¹ (m λ / d)
for 5 slits
θ₅ = sin⁻¹ (m λ 5)
for 10 slits
θ₁₀ = sin⁻¹ (m λ 10)
we can appreciate that for more slits the angle increases
the intensity of a series of slits is
I = I₀ sin²2 (N d/2) / sin² d/2)
when there are more slits (N) the peaks have greater intensity and are more acute (half width decreases)
let's analyze the claims
False
True The grid with more slits gives more angle separation increases
False
True The expression for the intensity of the diffraction peaks the intensity of the peaks increases with the number of slits as well as their spectral width decreases
False
The complete sentence is:
A calorimeter directly measures changes in temperature in order to calculate specific heat.
In fact, the amount of energy acquired/released by a substance is directly proportional to its change in temperature due to the equation

where Q is the amount of energy, m is the mass of the substance, Cs is the specific heat of the substance and
is the change in temperature. Therefore, by knowing Q, m and by measuring the change in temperature, it is possible to calculate Cs, the specific heat capacity of the substance.
In what may be one of the most remarkable coincidences in
all of physical science, the tangential component of circular
motion points along the tangent to the circle at every point.
The object on a circular path is moving in that exact direction
at the instant when it is located at that point in the circle. The
centripetal force ... pointing toward the center of the circle ...
is the force that bends the path of the object away from a straight
line, toward the next point on the circle. If the centripetal force
were to suddenly disappear, the object would continue moving
from that point in a straight line, along the tangent and away from
the circle.