Answer:
Explanation:
a ) F = (-kx + kx³/a²)
intensity of field
I = F / m
= (-kx + kx³/a²) / m
If U be potential function
- dU / dx = (-kx + kx³/a²) / m
U(x) = ∫ (kx - kx³/a²) / m dx
= k/m ( x²/2 - x⁴/4a²)
b )
For equilibrium points , U is either maximum or minimum .
dU / dx = x - 4x³/4a² = 0
x = ± a.
dU / dx = x - x³/a²
Again differentiating
d²U / dx² = 1 - 3x² / a²
Put the value of x = ± a.
we get
d²U / dx² = -2 ( negative )
So at x = ± a , potential energy U is maximum.
c )
U = k/m ( x²/2 - x⁴/4a²)
When x =0 , U = 0
When x= ± a.
U is maximum
So the shape of the U-x curve is like a bowl centered at x = 0
d ) Maximum potential energy
put x = a or -a in
U(max) = k/m ( x²/2 - x⁴/4a²)
= k/m ( a² / 2 - a⁴/4a²)
= k/m ( a² / 2 - a²/4)
a²k / 4m
This is the maximum total energy where kinetic energy is zero.
Answer:
the electric field is 42.8×10^6 N/C
Explanation:
let k be the coulomb constant, Q be the charge distribution , R be the radius of the disk and x be the distance from the center.
k = 8.98755×10^9 N×m^2/c^2
Q = 6.1×10^-6 C
R = 4.9×10^-2 m
x = 3.1×10^-3 m
Answer: 55.52 *10^-6 C= 55.52 μC
Explanation: In order to solve this question we have to take into account the following expressions:
potential energy stired in a capacitor is given by:
U=Q^2/(2*C) where Q and C are the charge and capacitance of the capacitor.
then we have:
Q^2= 2*C*U=
C=εo*A/d where A and d are the area and separation of the parallel plates capacitor
Q^2=2*εo*A*U/d=2*8.85*10^-12*1.9*10^-5*11*10^3/(1.2*10^-3)=
=55.52 *10^-6C
Answer:
80 meters high
Explanation:
The velocity of the balloon would be g*t (I won't calculate, but will us this later)
We know that the kinetic energy at the bottom equals the potential at the top.
KE = PE
1/2 * m * v^2 = m * g * h
1/2 * m * (g * t)^2 = m * g * h (substitution)
1/2 * m * g^2 * t^2 = m * g * h
1/2 * g * t^2 = h (simplification by dividing the commons between both sides)
h = 1/2 * 9.81 * 4^2
h = 78.48 m (roughly 80 m)
Given Information:
Resistance of circular loop = R = 0.235 Ω
Radius of circular loop = r = 0.241 m
Number of turns = n = 10
Voltage = V = 13.1 V
Required Information:
Magnetic field = B = ?
Answer:
Magnetic field = 0.00145 T
Explanation:
In a circular loop of wire with n number of turns and radius r and carrying a current I induces a magnetic field B
B = μ₀nI/2r
Where μ₀= 4πx10⁻⁷ is the permeability of free space and current in the loop is given by
I = V/R
I = 13.1/0.235
I = 55.74 A
B = 4πx10⁻⁷*10*55.74/2*0.241
B = 0.00145 T
Therefore, the magnetic field at the center of this circular loop is 0.00145 T
