Answer:
25 cm³
Explanation:
In the conversion of units, we know that are one cubic centimeters (cm³) in a milliliter (mL) .
1 milliliter = 1 cubic centimeter
25 milliliters = 25 cubic centimeters
Therefore, a volume of 25 milliliters is the same as a volume of 25 cubic centimeters.
This ultimately implies that, the volume of an object in milliliters is equivalent to its volume in cubic centimeters.
As the air becomes warmer, heat<span> is transferred </span>between<span> molecules and kinetic</span>energy<span> is created which produces </span>thermal energy<span>. As the molecules move faster to transfer </span>heat<span>, the </span>temperature<span> also increases.</span>
Answer:
Option B and Option D are true
Explanation:
We are given;
Number of atoms in block A = 800
Energy content in block A = 20 quanta
Number of atoms in block B = 200
Energy content in block B = 80 quanta
The energy of a system which is an extensive quantity,depends on the mass or number of moles of the system. However, at equilibrium, the energy density of the two copper blocks will be equal. That is, each atom of Cu in the two blocks will, on average, have the same energy. Because block A has 4 times more atoms than block B, it will have 4 times more quanta of energy. Thus, option B is therefore true while option A is false.
Temperature is a measure of the average kinetic energy of the atoms in a material. Now, if each atom in blocks A and B have the same average energy, then the temperatures of blocks A and B will be equal at equilibrium. Thus, option D is true.
Entropy of a system is an extensive quantity that depends on the the mass or number of atoms in the system. Because block A is bigger than block B, it will have higher entropy. However, that the specific entropy (the entropy per mole or per unit mass) is an intensive quantity -- it is independent of the size of a system. The molar entropy of blocks A and B are equal at equilibrium. Thus option C is false.
Answer:
Yes, the race car driver needs a faster reaction time than someone driving in a school zone.
Explanation.
For the sake of argument, let us consider
(i) a person driving at 35 mph in a school zone (as a normal driver);
(ii) a person driving at 60 mph in a school zone (as a racing driver).
Suppose a blind pedestrian crosses the road 0.1 miles (about 500 feet) in front of the driver.
The time before the normal driver hits the pedestrian is
(0.1 /35)*3600 = 10.3 seconds.
The time before the racing driver hits the pedestrian is
(0.1/60)*3600 = 6 seconds.
Because a reaction time of 6 seconds may be insufficient to avoid hitting the pedestrian, the racing driver needs a faster reaction time than the normal driver.
We can solve the problem by using Ohm's law.
The resistance of the person, with dry skin, is
. In order to be felt, the current must be at least
Ohm's law gives us the relationship between current and voltage:
where
I is the current
R the resistance
V the voltage
Using the data of the problem, we find that the minimum voltage needed is
