Answer: D
Explanation: Look at the figure, we can conclude that the correct answer is
X: Low potential energy
Y: High potential energy
Z: Flow of electrons
Because electrons flow where there is difference in potential energy. And electrons move from a region of high potential energy to a region of low potential energy.
Since the arrow is pointing to X, that means
Z is the flow of electrons, X is of low potential energy and Y is of high potential energy.
If the rock is just sitting there and you want to SLIDE it, then you have to push it with a force of at least
(251 kg) x (9.8 m/s²) x (μ) =
(2,459 Newtons) x (the coefficient of static friction on that surface)
Answer:
The answer to this is
6600 Hz to 19,800 Hz
Explanation:
The shape of the human ear is analogous to a closed ended pipe hence
we have λ = 4L or wavelength = 4 * length of the child ear
The frequency c/λ where c = speed of sound = 343 m/s
hence the child's audible range is multiples of 343/(4*0.13) =6600Hz
or 13200 Hz or 19,800 Hz
The generally quoted range of human hearing is 20 Hz to 20 kHz