A sound wave<span> in a steel rail </span>has<span> a </span>frequency of<span> 620 </span>Hz<span> and a </span>wavelength<span> of 10.5 ... Find the </span>speed<span> of </span>a wave<span> with a </span>wavelength of 5<span> m and a </span>frequency of<span> 68 </span>Hz<span>.</span>
Answer:
a) I = 464 kg m², b) K = 631 .6 J, c) v = 8.25 m / s
Explanation:
a) the moment of inertia of point particles is
I = ∑ m_i r_i²
in this case
I = 8 5² + 3 (-2) ² + 7 (-6) ²
I = 464 kg m²
b) The kinetic energy is
K = ½ I w²
K = ½ 464 1.65²
K = 631 .6 J
c) linear and angular velocity are related
v = w r
v = 1.65 5
v = 8.25 m / s
Given Information:
Power of bulb = w = 25 W
atts
distance = d = 9.5 cm = 0.095 m
Required Information:
Radiation Pressure = ?
Answer:
Radiation Pressure =7.34x10⁻⁷ N/m²
Explanation:
We know that radiation pressure is given by
P = I/c
Where I is the intensity of radiation and is given by
I = w/4πd²
Where w is the power of the bulb in watts and d is the distance from the center of the bulb.
So the radiation pressure becomes
P = w/c4πd²
Where c = 3x10⁸ m/s is the speed of light
P = 25/(3x10⁸*4*π*0.095²)
P = 7.34x10⁻⁷ N/m²
Therefore, the radiation pressure due to a 25 W bulb at a distance of 9.5 cm from the center of the bulb is 7.34x10⁻⁷ N/m²
Air flowing from areas of high pressure to low pressure creates wind.
