Answer:
4520 kJ
Explanation:
To make a substance transition phases an energy must be applied, this is know as the latent heat.
Water has a latent heat of 40.7 KJ/mol to turn into vapor.
The molecule of water has a molecular weight of 18. This means that a mol of water weights 18 grams.
With this we can convert the latent heat to use grams instead of mols
Now, the heat needed to vaporize water is simply:
Q = m * DHvap = 2000 g * 2.26 kJ/g = 4520 kJ
Answer:
Part A:
Part B:
Part C:
Explanation:
Part A:
We will use the following kinematics equation:
Part B:
We will use the same kinematics equation:
Part C:
The total time takes is 2t.
So the train moves a distance of
And the car moves a distance in Part A and in Part B:
So the total distance that the car traveled is
The difference between the train and the car is
Answer:
c. the speed of a planet is greatest when it is closest to the Sun.
Explanation:
Johannes Kepler was an astronomer who discovered that planets had elliptical orbits in the early 1600s (between 1609 and 1619).
The three (3) laws published by Kepler include;
I. The first law of planetary motion by Kepler states that, all the planets move in elliptical orbits around the Sun at a focus.
II. According to Kepler's second law of planetary motion, the speed of a planet is greatest when it is closest to the Sun.
Thus, the nearer (closer) a planet is to the Sun, the stronger would be the gravitational pull of the sun on the planet and consequently, the faster is the speed of the planet in terms motion.
III. The square of any planetary body's orbital period (P) is directly proportional to the cube of its orbit's semi-major axis.
Total work energy on the input side is WE = Fs; where F is a force acting on a mass to push it s distance. This is the so-called work function. Let fs = we, which is the work energy (useful energy) attained as output when WE is input.
<span>From the conservation of energy WE = Fs = fs - kNs = Total Output energy. Net force f = F - kN where kN is friction force acting against the pushing (input) force F. In the real world, there is always friction at some level. That is kN > 0 always. </span>
<span>Thus Fs = (F - kN)s; kNs = the energy lost to friction where k is the friction coefficient and N is the normal force on the surface(s) where the friction is generated. By definition, efficiency = fs/Fs = useful work/work input. Clearly fs = Fs - kN < Fs . Thus efficiency = fs/Fs < 1.00, which means output fs < Fs the input whenever kN > 0, which in the real world it always is. </span>
<span>The short answer is...output is always less than input because of friction and, sometimes, other losses like wind drag (which is a form of friction anyway).</span>