Answer:
Since incident wave and its reflected part in opposite phase superimpose on each other
So correct answer will be
Option B
Explanation:
Here we know that the wave reflection is done by rigid boundary
So when wave is reflected by the boundary then its phase is reversed by 180 degree
so the reflected wave is in reverse phase from the boundary
so we can superimpose the reflected part with incident wave to dine the resultant wave
So the phenomenon is given as follow
Answer: 42.49
Explanation:
To solve this, we need to keep in mind the following:
While the sphere hangs it is under the effect of gravity. It is creating a Angle of 90° taking the roof as a reference.
Gravity can be noted as a Acceleration Vector. The magnitud for Earth's Gravity is a constant: 9.81
The acceleration of the Van will affect the sphere also, but this accelaration will be on the X-axis and perpendicular to the gravity. Because this two vectors are taking action under the sphere they will create a angle. This angle can be measured as a relation of the two magnitudes.
Tangent (∅) = Opossite Side / Adyacent Side
By trigonometry, we know the previous formula. This formula allows us to find the Tangent of a angle as a relation between the two perpendiculars magnitudes. In this case the Opossite Side will be the Gravity Accelaration, while the Adyancent Side is the Van's Acceleration.
(1) Tangent (∅) = Gravity's Acceleration (G) / Van's Acceleration (Va)
Searching for the Va in (1)
Va = G/Tan(∅)
Where ∅ in this case is equal to 13.0°
Va = 9.81 / Tan(13.0°)
Va = 42.49
The vans acceleration need to be 42.49 to create an angle of 13° with the Van's Roof