Answer:
Explanation:
In a molecule, atoms are bonded together by single, double, or triple bonds. An atom has a nucleus surrounded by electrons. ... So another difference between atoms and molecules is that when similar atoms combine together in varying numbers, molecules of different properties can be formed.
Answer:
T
Explanation:
= magnitude of current in each wire = 2.0 A
= length of the side of the square = 4 cm = 0.04 m
= length of the diagonal of the square = 
a = (0.04) = 0.057 m
= magnitude of magnetic field by wires at A and C
T
= magnitude of magnetic field by wire at B
T
Net magnitude of the magnetic field at D is given as
T
Answer:
100 m
Explanation:
From the question,
R = Lρ/A.................... Equation 1
Where R = resistance of the wire, L = length of the wire, ρ = resistivity of the wire, A = cross sectional area of the wire.
But,
A = πr².................... Equation 2
Where r = radius of the wire.
Substitute equation 2 into equation 1
R = Lρ/πr²
Make L the subject of the equation
L = Rπr²/ρ...................... Equation 3
Given: R = 40 Ω, r = 5×10⁻⁴ m, ρ = 3.14×10⁻⁷ Ωm
Constant: π = 3.14
Substitute these values into equation 3
L = [40×3.14×( 5×10⁻⁴)²]/ (3.14×10⁻⁷)
L = 40×3.14×25×10⁻⁸/(3.14×10⁻⁷)
L = 100 m
Hence the length of the wire is 100 m
Answer:
The gravitational potential energy of a system is -3/2 (GmE)(m)/RE
Explanation:
Given
mE = Mass of Earth
RE = Radius of Earth
G = Gravitational Constant
Let p = The mass density of the earth is
p = M/(4/3πRE³)
p = 3M/4πRE³
Taking for instance,a very thin spherical shell in the earth;
Let r = radius
dr = thickness
Its volume is given by;
dV = 4πr²dr
Since mass = density* volume;
It's mass would be
dm = p * 4πr²dr
The gravitational potential at the center due would equal;
dV = -Gdm/r
Substitute (p * 4πr²dr) for dm
dV = -G(p * 4πr²dr)/r
dV = -G(p * 4πrdr)
The gravitational potential at the center of the earth would equal;
V = ∫dV
V = ∫ -G(p * 4πrdr) {RE,0}
V = -4πGp∫rdr {RE,0}
V = -4πGp (r²/2) {RE,0}
V = -4πGp{RE²/2)
V = -4Gπ * 3M/4πRE³ * RE²/2
V = -3/2 GmE/RE
The gravitational potential energy of the system of the earth and the brick at the center equals
U = Vm
U = -3/2 GmE/RE * m
U = -3/2 (GmE)(m)/RE
Answer:
0.833 N
Explanation:
Formula for Kinetic Energy 
Formula for Potential Energy 
First we need to find the vertical distance between the maximum-angle position and the pendulum lowest point:
Using the swinging point as the reference, the vertical distance from the maximum-angle (34 degree) position to the swinging point is:
At the lowest position, pendulum is at string length to the swinging point, which is 1.2 m. Therefore, the vertical distance between the maximum-angle position and the pendulum lowest point would be
y = 1.2 - 1 = 0.2 m.
As the pendulum is traveling from the maximum-angle position to the lowest point position, its potential energy would be converted to the kinetic energy.
By law of energy conservation:
Substitute 
and y = 0.2 m:
At lowest point, pendulum would generate centripetal tension force on the string:
We can substitute mass m = 0.25, rotation radius L = 1.2 m and v = 2 m/s:
