In a closed system, energy in form of heat (work) can be exchanged but not matter.
The answer to your question is C.
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Answer:
A) L = 0.496 m, B) the movement of the elevator upwards decreases the angular velocity of the pendulum
Explanation:
A) The motion of a simple pendulum is a harmonic motion with angular velocity
w² = g /L
angular velocity and frequency are related
w = 2π f
we substitute
4π² f² = g /L
L =
let's calculate
L = 9.8 / 4 pi² 0.5
L = 0.496 m
B) To see the effect of the elevator acceleration (aₐ), let's use Newton's second law.
At the acceleration from the vertical direction upwards, let's decompose it is a component parallel to the movement and another perpendicular
sin θ = a_parallel / aₐ
a_parallel = aₐ sin θ
this component of the acceleration is in the opposite direction to the movement of the system, so it must be negative
- W sin θ = m (a - a_parallel)
- mg sin θ = m ()
all angles are measured in radians, therefore the angular displacement is
s = L θ
We solve the system for small angles
sin θ = θ
we substitute
- mg θ + m aₐ θ = m L
this is the same equation of the simple pendulum therefore the angular velocity is
w² =
When analyzing this expression, we see that the movement of the elevator upwards decreases the angular velocity of the pendulum
Answer: The length L of the wire used to construct the coil is 191.4m
Explanation: Please see the attachments below
Answer:
(B) a whole number of wavelengths.
Explanation:
Two beams of coherent light start out at the same point in phase and travel different paths to arrive at point P. If the maximum destructive interference is to occur at point P, the two beams must travel paths that differ by a whole number of wavelengths.
When the resultant effect of the combination of two identical waves result in their annihilation or complete cancellation of the effect of each other, destructive interference takes place. Hence to have two wave sources producing waves that have the same frequency wavelength and amplitude and which are always in phase with each other or have a constant phase difference are said to be Coherent source