sound travels through a medium in mechanical waves a mechanical wave is a disturbance that moves and transports energy from one place to another through a medium
Answer:
A) is repelled by the sphere.
Explanation:
When a charged insulated rod is touched with an insulated conducting sphere , some charge on the rod gets transferred to the sphere . So they become similarly charged . We all know that there is repulsion when two similarly charged object are brought near to each other . Hence here too there will be repulsion between the rod and the sphere when the rod is brought near the sphere.
Answer:
The velocity of the flow at point 1 is nine times greater than the velocity at point 2.
Explanation:
We know that the same volume of water entering through point 1 must exit through point 2.
The volume of water per unit of time or the volumetric flow is defined by:
![V_{flow}=v*A\\ where:\\V_{flow}= flow [m^3/s]\\v=velocity[m/s]\\A=area [m^2]](https://tex.z-dn.net/?f=V_%7Bflow%7D%3Dv%2AA%5C%5C%20where%3A%5C%5CV_%7Bflow%7D%3D%20flow%20%5Bm%5E3%2Fs%5D%5C%5Cv%3Dvelocity%5Bm%2Fs%5D%5C%5CA%3Darea%20%5Bm%5E2%5D)
If 
therefore

Multiply by (1000 meters / 1 km).
Then multiply by (1 hour / 3600 seconds).
Both of those fractions are equal to ' 1 ', because the top
and bottom numbers are equal, so the multiplications
won't change the VALUE of the 72 km/hr. They'll only
change the units.
(72 km/hour) · (1000 meters / 1 km) · (1 hour / 3600 seconds)
= (72 · 1000 / 3600) (km·meter·hour / hour·km·second)
= 20 meter/second