Answer:
Concrete
Explanation:
The speed at which sound propagates is medium dependent. As one of the forms of mechanical waves, sound requires a material medium for propagation from place to place.
- Sound travels with the least speed in air because air particles are far apart and they are randomized.
- Sound travels with the greatest speed in solids. Concrete is the only solid material given in the choice.
The speed of sound increases from air to liquid and to solid.
B)is pills everything to the surface of the earth not sure about A
Explanation:
PE= mgh
6 J= (3m) (9.81 m/s2) (mass)
mass=( 6)/(3×9.81)
mass= 0.20 Kg
Answer:
Pls mark me brainliest
Explanation:
The wheel and axle is a simple machine consisting of a wheel attached to a smaller axle so that these two parts rotate together in which a force is transferred from one to the other.
Answer: A
The diffusion time through the edge is double the diffusion time through the center.
Explanation:
Only the diffusion coefficient, thickness, surface area, distance affects the time it takes a gas such as oxygen to diffuse a given in a medium. The Diffusion time increases with the square of diffusion distance Also, the Increased surface area increases the rate of diffusion or the diffusion time, whereas a thicker membrane reduces the rate of diffusion or time it takes the gas to be permeable. Also, The greater the distance that a substance must travel, the slower the rate of diffusion The diffusion coefficient determines the time it takes a gas to diffuse. Also the Diffusion time is inversely proportional to the diffusion coefficient.
Now, If the edge of a contact lens is double the thickness of the central portion of the lens, then it will take more time for the gas to diffuse through the thicker portion. since its edge is double the central position, then the diffusion time will also be doubled. So Option A is the best answer-
The diffusion time through the edge is double the diffusion time through the center.
