Answer:
85.31 N
Explanation:
Given,
Radius of Earth = 3960 miles = 6373 Km
Weight of Astronaut at Sea level = 200lb = 90.72 Kg
Altitude of Astronaut above Earth = 125 miles = 201.17 km
We know that,
-------------------------- (1)
where,
F = force on the object due to gravity also called the weight
m = mass of the object = 200 lb = 90.71 kg
g = acceleration due to gravity = 9.8 m/s²
Also,
-------------------(2)
where,
F = force due to gravity
G = Gravitational constant =
Nm²/kg²
M = mass of the Earth = 
r = distance between the two objects
here, r = (6373+201.17)km = 6574170 m
From equation (1),

Putting value of m in equation (2)


Answer:
The charge on the dust particle is 
Explanation:
From the question we are told that
The length is 
The width is 
The charge is 
The mass suspended in mid-air is 
Generally the electric field on the carpet is mathematically represented as

Where
is the permittivity of free space with value 
substituting values


Generally the electric force keeping the dust particle on the air equal to the force of gravity acting on the particles

=> 
=> 
=> 
=> 
Answer:
(a) 0.0178 Ω
(b) 3.4 A
(c) 6.4 x 10⁵ A/m²
(d) 9.01 x 10⁻³ V/m
Explanation:
(a)
σ = Electrical conductivity = 7.1 x 10⁷ Ω-m⁻¹
d = diameter of the wire = 2.6 mm = 2.6 x 10⁻³ m
Area of cross-section of the wire is given as
A = (0.25) π d²
A = (0.25) (3.14) (2.6 x 10⁻³)²
A = 5.3 x 10⁻⁶ m²
L = length of the wire = 6.7 m
Resistance of the wire is given as


R = 0.0178 Ω
(b)
V = potential drop across the ends of wire = 0.060 volts
i = current flowing in the wire
Using ohm's law, current flowing is given as


i = 3.4 A
(c)
Current density is given as


J = 6.4 x 10⁵ A/m²
(d)
Magnitude of electric field is given as


E = 9.01 x 10⁻³ V/m
Answer:
Q = ba⁴ * ε₀
Explanation:
From Gauss's Law, we know that
flux Φ = Q / ε₀
where ε₀ = 8.85e-12 C²/N·m²
and also,
Φ = EAcosθ
The field is directed along the x-axis, so that all of the flux passes through the side of the cube at x = a. This means that θ = 0º, and thus
Φ = EAcos0
Φ = EA
E = bx² meanwhile, we are interested in the point where x = a, so we substitute and then
E = ba²
Since A = a² for the cube face, we have
Q / ε₀ = E * A
Q / ε₀ = ba² * a²
so that
Q = ba⁴ * ε₀
Answer: The direction of the electric field, E→, is pointed in the +y direction.
Explanation:
One can use the right hand rule to illustrate the direction of travel of an electromagnetic and thereby get the directions of the electric field, magnetic field and direction of travel of the wave.
The right hand rule states that the direction of the thumb indicate the direction of travel of the electromagnetic wave (<em>in this case the -z direction</em>) and the curling of the fingers point in the direction of the magnetic field B→ (<em>in this case the +x direction</em>), therefore, the electric field direction E→ is in the direction of the fingers which would be pointed towards the +y direction.