Answer:
The extension of the wire is 0.362 mm.
Explanation:
Given;
mass of the object, m = 4.0 kg
length of the aluminum wire, L = 2.0 m
diameter of the wire, d = 2.0 mm
radius of the wire, r = d/2 = 1.0 mm = 0.001 m
The area of the wire is given by;
A = πr²
A = π(0.001)² = 3.142 x 10⁻⁶ m²
The downward force of the object on the wire is given by;
F = mg
F = 4 x 9.8 = 39.2 N
The Young's modulus of aluminum is given by;
Where;
Young's modulus of elasticity of aluminum = 69 x 10⁹ N/m²
Therefore, the extension of the wire is 0.362 mm.
Complete Question:
The mass of the sphere is 0.151 kg. What is the rotational inertia of the wheel? Recall that the radius of the sphere is about 0.312 m. Express your answer with three significant figures in Kg.m².
Answer:
I = 5.88*10⁻³ kg.m²
Explanation:
It can be showed that the rotational inertia (or moment of inertia) for a solid sphere of radius r and mass m, regarding any axis passing through the center of the sphere, can be expressed as follows:
I = (2/5)*m*r² (1)
where m= 0.151 kg, and r =0.312 m. (Our givens).
Replacing in (1) we have:
I = (2/5)*0.151 kg*(0.312m)² = 5.88*10⁻³ kg.m²
Answer:
the oscillations of the electrons must be in the 10⁸ Hz = 100 MHz range
Explanation:
The speed of a wave of radio, television, light, heat, all are manifestations of electromagnetic waves that are oscillations of electric and magnetic fields that support each other, the speed of all these waves is the same and the vacuum is equal to c = 3 108 m / s
All waves have a relationship between the speed of the wave, its frequency and wavelength
c = λ f
f = c /λ
for this case lam = 1 m
f = 3 10⁸/1
f = 3 10⁸ Hz
the oscillations of the electrons must be in the MHz range
It should be clarified that the speed of light in air is a little lower
n = c / v
v = c / n
the refractive index of vacuum is n = 1 and the refractive index of air is n = 1.000002
