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.
Answer:
C. tiny particles called charges flowing through the wires.
Explanation:
<h3> Hello!</h3>
An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume.
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Answer:
Δd = 
Explanation:
As 
, when the car is making full stop, 
. 
. Therefore,
Apply the same formula above, with 
and 
, and the car is starting from 0 speed, we have
As 
. After 
, the car would have traveled a distance of
Hence 
As 
we can simplify 
After t time, the train would have traveled a distance of 
Therefore, Δd would be 
