Answer:
<em>Pure water </em><em>won’t conduct electricity</em>
<em>Option A</em>
Explanation:
Pure water doesn’t contain salts or impurities. It is the salts that dissociate to form ions that act as charge carriers in conducting solutions. For a medium to conduct electricity it should have carriers to carry the electrical charge.
Thus absence of charge carriers make pure water non conducting. Charge carriers in metals are electrons and in ionic solutions they are positive and negative ions.
Tap water, aquarium water and ocean water contains dissolved electrolytes. When electricity is passed through them the electrolytes dissociates into ions and these ions conduct electricity.
Answer:
B. 25 feet
Explanation:
In most cities in US, passenger car brakes must stop a car moving at 20 miles per hour at 25 feet.
Therefore, the correct option is "B" 25 feet
Answer:
The mother has to sit 2.17 ft from the center on the other side of the seesaw.
Explanation:
We are trying to find the sum of torques given by the weights of mother and daughter to be zero.
If the torque of the daughter on one side of the pivoting point is given by:
5.5 ft x 63.5 lb x g = 349.25 g ft lb
we need that the absolute value of the torque exerted by the mom (160.9 lb) to be the same in magnitude (and of course opposite direction). So we assume that "d" is the distance at which the mother locates to make this torque equal in magnitude to her daughter's torque:
d x 160.9 lb x g = 349.25 g ft lb
d = 2.17 ft
3 as a single number is considered a sf
Answer:
When the volume increases or when the temperature decreases
Explanation:
The ideal gas equation states that:
where
p is the gas pressure
V is the volume
n is the number of moles of gas
R is the gas constant
T is the gas temperature
Assuming that we have a fixed amount of gas, so n is constant, we can rewrite the equation as
which means the following:
- Pressure is inversely proportional to the volume: this means that the pressure decreases when the volume increases
- Pressure is directly proportional to the temperature: this means that the pressure decreases when the temperature decreases
