Answer:A
Explanation:matter normally occurs in three phases;solid, liquid and gases. They may change from one phase to another due to temperature difference.
The molecules that makes up solids are held together by bonds. When heat is added,the molecules begin to move as a result,the bonds break and it turns to liquid.this process is called melting. The reverse of melting is freezing.
Liquid are made up of molecules that moves more freely than solids. When heat is added to liquid,the molecules gain more energy and begins to move faster. This causes them to turn to gases.
This process is called evaporation. It occurs at different temperature for different substances.
The particles of gases move more faster and are separated by large distances. A gas can change back to a liquid through condensation.
Answer:
The maximum speed at which the car can safety travel around the track is 18.6m/s.
Explanation:
Since the car is in circular motion, there has to be a centripetal force 
. In this case, the only force that applies for that is the static frictional force 
between the tires and the track. Then, we can write that:
And since 
and 
, we have:
Now, if we write the vertical equation of motion of the car (in which there are only the weight and the normal force), we obtain:
Substituting this expression for 
and solving for 
, we get:
Finally, plugging in the given values for the coefficient of friction and the radius of the track, we have:
It means that in its maximum value, the speed of the car is equal to 18.6m/s.
The answer to the question is A
The only correct statement on that list is <em>choice-C</em>: If a positively charged rod is brought close to a positively charged object, the two objects will repel.
Answer:
It's C because if you were trying to put it at rest that means you would put it on a Balanced surfest
