Answer:
0.35 m
Explanation:
Constructive interference occurs when the difference in the distance between the two speakers is
0, λ, 2λ,...
Here λ = v/f = 343/490 = 0.7m
The first point of interference is the initial point which would mean the distance is the trivial solution of 0 .
A microphone is placed half-way between the speakers and then moved along the line joining the two speakers until the first point of constructive interference is found.
Let x be the distance from the midpoint to the next interference.
This occurs when 1.5 + x -(1.5 - x) = 0.7
so 2x = 0.7 which means x = 0.7/2 = 0.35m
Three practical uses of electromagnets would be
Light. The waves
Electric locks. The bolts that are used by the
coils
Cranes. The electric ones that are found in
scraps
Cars computers washing machines all use
Electromagnets . Even CD players DVDs
Players
The answer for the online test is going to be the last one, D
Answer:
The position is 8.18cm from the mirror.
Nature is b=virtual
Size is 1.82cm
Explanation:
Note that for a convex mirror, the image distance and the focal length are negative;
Given
Object height H0 = 4cm
object distance u = 18cm
Radius of curvature R = 30cm
Since f = R/2
f = 30/2
f = -15cm
Recall that:
Since the image distance is negative, this shows that the image is a virtual image.
To get the size:
The ozone layer is beneficial because it protects us from the ultraviolet (UV) rays from the sun. Without it, survival would be difficult. It is harmful by containing all the pollution and chemicals . That damages our lungs and causes chest pain, coughing,etc.
