For a stationary siren on a firehouse is blaring at 81Hz. Assume the speed of sound to be 343m/s, the frequency perceived is mathematically given as'
F=81.721Hz
<h3>What is the frequency perceived by a firefighter racing toward the station at 11km/h?</h3>Generally, the equation for the doppler effect is mathematically given as
Therefore
F=81(343+3.05556)/343
F=81.721Hz
In conclusion, the frequency is
F=81.721Hz
Read more about frequency
Answer:
The correct option is 'c':electron,proton,helium nucleus
Explanation:
The De-Broglie's wavelength of particle is given by
Thus we can see that wavelength is inversely related to mass of the particle since 'h' (Plank's constant) and velocity is same for all the particles
Thus we conclude that the the lightest particle will have the most wavelength
Electron being the lightest of the 3 particles will have the largest wavelength thus the correct option is 'c'. Since electron has the largest wavelength followed by proton and the least wavelength among the 3 is of helium.
Answer:
a) Gravitational potential energy = 399 J
b) Gravitational potential energy = 66.5 J
c) Gravitational potential energy = 0 J
Explanation:
Hi there!
Please, see the attached figure for a better understanding of the problem.
a) When the ropes are horizontal, the height of the child, relative to the child's lowest position, is 2.10 m (see figure).
The gravitational potential energy is calculated as follows:
PE = mgh
Where:
PE = potential energy.
mg = weight of the child
h = height.
Then when the ropes are horizontal, the potential energy will be:
PE = 190 N · 2.10 m = 399 J
b) When the ropes make a 34.0° with the vertical, the height of the child is 2.10 m minus x (see figure). To find x, we can use trigonometry of right triangles:
cos angle = adjacent side / hypotenuse
cos 34.0° = x / 2.10 m
x = 2.10 m · cos 34.0° = 1.75 m
Then, the height of the child relative to the lowest position is
(2.10 m - 1.75 m) = 0.35 m
Therefore, the gravitational potential energy will be:
PE = 190 N · 0.35 m
PE = 66.5 J
c) When the child is at the bottom of the circular arc the height is zero (the child is at the lowest position), then, the gravitational potential energy will be zero.
