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
A comet is long and also bright, which has a blue-ish color to it.
Best Regards, Mike
Mass is the amount of matter present in an object, it also determines the strength of the mutual gravitational force of an object to another object. Volume is the amount of space that the object occupies. Meanwhile, density is the amount of mass per volume of an object, with that formula, we can say that density is directly proportional to the mass but indirectly proportional to the volume.
Answer:
The type of light and the material of lenz.
Explanation:
1) As the investigation is based on how the thickness of a lens effect the other variable. Thickness of the lenz is independent variable. So Lidia has to experiment with the different thicknesses in order to find the effect on dependent variable.
2) As the investigation is based to find the point where the beam of light is focused. It's a dependent variable and Lidia has no control over it. So the only thing she can do is to measure and observe how it respond to the changes in independent variable.
3) For conclusion, she has to make sure that the other variables are not effecting the output or results that is the beam point where the light is focused. So she must have to kept constant the type of light and material of lenz otherwise she won't be able to discriminate the effect of thickness of lenz from other causes.
Answer:
The charge is moving with the velocity of
.
Explanation:
Given that,
Charge 
Angle = 35°
Magnetic field strength 
Magnetic force 
We need to calculate the velocity.
The Lorentz force exerted by the magnetic field on a moving charge.
The magnetic force is defined as:


Where,
F = Magnetic force
q = charge
B = Magnetic field strength
v = velocity
Put the value into the formula




Hence, The charge is moving with the velocity of
.