Answer:
letter B
none zero digit are significant figures
Answer:
The frequencies are 
Explanation:
From the question we are told that
The length of the ear canal is 
The speed of sound is assumed to be 
Now taking look at a typical ear canal we see that we assume it is a closed pipe
Now the fundamental harmonics for the pipe(ear canal) is mathematically represented as

substituting values


Also the the second harmonic for the pipe (ear canal) is mathematically represented as
substituting values
Given that sound would be loudest in the pipe at the frequency, it implies that the child will have an increased audible sensitivity at this frequencies
Answer:
Frictional force, F = 45.9 N
Explanation:
It is given that,
Weight of the box, W = 150 N
Acceleration, 
The coefficient of static friction between the box and the wagon's surface is 0.6 and the coefficient of kinetic friction is 0.4.
It is mentioned that the box does not move relative to the wagon. The force of friction is equal to the applied force. Let a is the acceleration. So,



Frictional force is given by :


F = 45.9 N
So, the friction force on this box is closest to 45.9 N. Hence, this is the required solution.
It would take 500 seconds, because 2500 divided by 5 is 500
Answer:
2.1 × 10⁻⁵ T
Explanation:
Given:
Inner radius, r = 4 mm = 0.004 m
Outer radius, R = 25 mm = 0.025 m
Current, I = 4 A
Distance of the point from the center, a = 17 mm = 0.017 m
μ₀ = 4π × 10⁻⁷ T·m/A
Now,
For the hollow cylinder magnetic field (B) is given as:
on substituting the respective values, we get
or
B = 2.1 × 10⁻⁵ T