The speed of an object in a set direction is its velocity.
Answer:
Explanation:
so a mechanical wave transfers energy through a medium but unlike other waves that move through very long distances
the distance of the mechanical wave is different
Answer:
Part 1 
Part 2 
Part 3 
Explanation:
Given
Number of protons 
Radius of nucleus 
Distance of the electrons 
Part 1
Electric field produced by just outside its surface

Part 2
Electric field produced by just outside its surface

Part 3
The net electric field inside a uniform shell of negative charge is zero because the electric flux lines cancel out each other
hence, the solution is
Part 1 
Part 2 
Part 3 
a . true hardness and density are physical properties
Density = mass/volume
= 4300/10000
= 0.43 g/mL.
Therefore density of liquid propane is 0.43 g/mL.
Hope this helps!