Answer:
C
Explanation:
The electric field inside a conductor is always zero if the charges inside the conductor are not moving.
Since the electron are not moving then they must be in electrostatic equilibrium which means the electric field inside the conductor is zero. if the electric field existed inside the conductor then there will be net force on all the electrons and the electrons will accelerate.
Answer:
The intensity of sound wave at the surface of the sphere 
Explanation:
B = Bulk modulus
Intensity, 
The amplitude of oscillation of the sphere is given by:


Substitute v and A into Pmax




The intensity of the sound wave at a distance is given by:


Apply Newton's second law to the person's motion:
F = ma
F = net force, m = mass, a = acceleration
Given values:
m = 50.8kg, a = 3.50m/s²
Plug in and solve for F:
F = 50.8(3.50)
F = 178N
Your answer is 20
just take 1,200 divided by 60 [second] :)