Answer:
A vacuum
Explanation:
Sound waves are examples of mechanical waves. Mechanical waves are waves which are transmitted through the vibrations of the particles in a medium.
For example, sound waves in air consist of oscillations of the air particles, which vibrate back and forth (longitudinal wave) along the direction of propagation of the wave itself.
Given this definition of mechanical wave, we see that such a wave cannot propagate if there is no medium, because there are no particles that would oscillate. Therefore, among the choices given, the following one:
a vacuum
represent the only situation in which a sound wave cannot propagate through: in fact, there are no particles in a vacuum, so the oscillations cannot occur. In all other cases, instead, sound waves can propagate.
The Hubble Telescope or Hubble Space Telescope (HST) is designed to take images found within the solar system. It is a low-orbit kind of telescope that helped a lot of scientists in proving some theories in astrophysics and the dimensions of the Universe. It was launched in 1990s and since then has been in space taking up good quality images that would help scientists learn more from space explorations.
Option ( c ) is correct.
Using the formula for power
P= power
i= current= 0.4 A
R= resistance= 30 ohm
so power= (0.4)² (30)
Power=4.8 W
