B: Extension Lines! You could have just searched this up on google
Answer:
dT(t)/dt = k[T5 - T(t)]
Explanation:
Since T(t) represents the temperature of the object and T5 represents the temperature of the surroundings, according to Newton's law of cooling, the rate at which an object's temperature changes is directly proportional to the difference in temperature between the object and the surrounding medium, that is dT(t)/dt ∝ T5 - T(t)
Introducing the constant of proportionality
dT(t)/dt = k[T5 - T(t)]
which is the desired differential equation
Answer:
The angle of incidence when the reflected ray is perpendicular to the incident ray = 45°
Explanation:
According to Snell's Law,
n₁ sin θ₁ = n₂ sin θ₂
When the angle between the incident ray and reflected ray is 90°, the angle of incidence is θ₁ and the angle of reflection, θ₂ = 90° - θ₁ and the index of refraction in the Snell's Law for both media would be the same, n₁ = n₂ = n
n sin θ₁ = n sin (90° - θ₁)
Note that from trigonometric relations,
Sin (90° - θ₁) = cos θ₁
n sin θ₁ = n cos θ₁
(sin θ₁)/(cos θ₁) = 1
tan θ₁ = 1
θ₁ = arctan 1 = 45°
Hope this Helps!!!
Because 'acceleration' does NOT mean 'speeding up'.
It means ANY change in motion ... speeding up, slowing down,
or changing DIRECTION.
When traveling a roundabout, or any curved path, the direction
is constantly changing even if the speed is constant, so there is
constant acceleration going on.
Answer:
The first harmonic is: 250Hz, second harmonic 500Hz, third harmonic 750Hz.
Explanation:
Use the frequency f, speed v, and wavelentgh L relationship:

We are given the speed v=400 m/s. The base wavelength on a string of length 80cm is twice the length of the string (a "half wave" along the full length of the string), so:

The fundamental frequency (first harmonic) is 250 Hz
The second harmonic is produced by one full wave across the string (adding one node in the middle), so L=80cm in this case, therefore the second harmonic frequency is: f2 = 2*250=500Hz
the third harmonic add another node (and a half wave) to the pattern and the wavelength will be 2/3 of 80cm, so f3=3*250Hz = 750Hz