Answer:
I = 4.75 A
Explanation:
To find the current in the wire you use the following relation:
(1)
E: electric field E(t)=0.0004t2−0.0001t+0.0004
ρ: resistivity of the material = 2.75×10−8 ohm-meters
J: current density
The current density is also given by:
(2)
I: current
A: cross area of the wire = π(d/2)^2
d: diameter of the wire = 0.205 cm = 0.00205 m
You replace the equation (2) into the equation (1), and you solve for the current I:
Next, you replace for all variables:
hence, the current in the wire is 4.75A
Answer:
use the kinematics equations and solve for time, after that use dleta dx=Vi*delta time
why does the baseball have to be autographed?
Answer:
The potential at the center of the sphere is -924 V
Explanation:
Given;
radius of the sphere, R = 0.22 m
electric field at the surface of the sphere, E = 4200 N/C
Since the electric field is directed towards the center of the sphere, the charge is negative.
The Potential is the same at every point in the sphere, and it is given as;
-------equation (1)
The electric field on the sphere is also given as;
Substitute in the value of q in equation (1)
Therefore, the potential at the center of the sphere is -924 V
To solve the problem it is necessary to refer to the definition of entropy.
Entropy is defined aso
Where,
Heat exchange
T = Temperature
Since the heat exchange is conserved and it is an isothermal process where the temperature remains constant the change in entropy remains the same, ie 
(Reamins same)
Therefore the correct answer is C.
