Answer:
Ф = 239.73 rad
Explanation:
α = 12 + 15×t
W = ∫α×dt
= ∫(12 + 5×t)×dt
= 12×t + 2.5×t^2
then:
Ф = ∫W×dt
= ∫(12×t + 2.5×t^2)dt
= 6×t^2 + 5/6×t^3
therefore the angle at t = 4.88s is:
Ф = 6×(4.88)^2 + 5/6×(4.88)^3
= 239.73 rad
The lights are wired in PARALLEL.
In fact, when the lights are connected in parallel, they are connected on separate branches to the source of voltage, so if one light bulb burns out, the other lights continue to work because the current continues to flow in the other branches of the circuit.
Vice-versa, if the light bulbs are connected in series, they are on the same branch This means that if one of them burns out, the circuit is open in that point, so the current cannot flow anymore and the other light bulbs turn off as well.
Person standing on A will hear the loudest sound
Explanation:
The intensity of a sound wave (which is proportional to the loudness of the sound) follows an inverse square law, which is:

where
I is the intensity of the wave
r is the distance from the source of the sound
This equation means that the intensity of the sound wave (and therefore, its loudness) is inversely proportional to the square of the distance from the source: therefore,
- As we get closer to the source of sound, the loudness increases
- As we move away from the source of sound, the loudness decreases
Therefore, the person that will hear the loudest sound is the one standing closer to the source, and therefore person A.
Learn more about sound waves:
brainly.com/question/4899681
#LearnwithBrainly
Answer:
≅50°
Explanation:
We have a bullet flying through the air with only gravity pulling it down, so let's use one of our kinematic equations:
Δx=V₀t+at²/2
And since we're using Δx, V₀ should really be the initial velocity in the x-direction. So:
Δx=(V₀cosθ)t+at²/2
Now luckily we are given everything we need to solve (or you found the info before posting here):
- Δx=760 m
- V₀=87 m/s
- t=13.6 s
- a=g=-9.8 m/s²; however, at 760 m, the acceleration of the bullet is 0 because it has already hit the ground at this point!
With that we can plug the values in to get:




Answer:
a) m_v = m_s ((
)² - 1) , b) m_v = 1.07 10⁻¹⁴ g
Explanation:
a) The angular velocity of a simple harmonic motion is
w² = k / m
where k is the spring constant and m is the mass of the oscillator
let's apply this expression to our case,
silicon only
w₉² =
k = w₀² m_s
silicon with virus
w² =
k = w² (m_v + m_s)
in the two expressions the constant k is the same and q as the one property of the silicon bar, let us equal
w₀² m_s = w² (m_v + m_s)
m_v = (
)² m_s - m_s
m_v = m_s ((
)² - 1)
b) let's calculate
m_v = 2.13 10⁻¹⁶ [(
)² - 1)]
m_v = 1.07 10⁻¹⁴ g