Which of the following is true for sound waves? They require a medium
They are unrelated to vibrations.
They can travel in a vacuum
They cannot travel through liquids
None of the above

Explanation:

Answer

λ α

f

1

Wave velocity = Wavelength × Frequency

Thus, we can say that wavelength is inversely proportional to the frequency.

FALSE - Only electromagnetic waves can travel through a vacuum; mechanical waves such as sound waves require a particle-interaction to transport their energy. There are no particles in a vacuum.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.