"Three short blasts" sound signal alerts others when a boat is backing up based on the boating safety rule. The short blast is a sound which has one second period, thus three short blasts mean three of this kind of sound. The sound signal is used for alerting anything surrounding the boat to avoid a collision.
The energy an object has due to its motion is called kinetic energy.
Answer:
a. The spheres will attract each other.
Explanation:
When two conducting spheres are connected by a conducting wire and a negatively charged rod is brought near it then this will induce opposite (positive) charge at the nearest point on the sphere and by the conservation of charges there will also be equal amount of negative charge on the farthest end of this conducting system this is called induced polarization.
- When the conducting wire which joins them is cut while the charged rod is still in proximity to of one of the metallic sphere then there will be physical separation of the two equal and unlike charges on the spheres which will not get any path to flow back and neutralize.
- Hence the two spheres will experience some amount of electrostatic force between them.
Explanation:
It is given that,
= -40 mi/h, = -40 mi/h
The negative sign indicates that x and y are decreasing.
We have to find 
. Equation for the given variables according to the Pythagoras theorem is as follows.
Now, we will differentiate each side w.r.t 't' as follows.
or, 
So, when x = 4 mi, and y = 3 mi then z = 5 mi.
As,
= 
= 
= 52
Thus, we can conclude that the cars are approaching at a rate of 52 mi/h.
