Answer:
- Option B) Absorbed energy results in the change in potential energy.
Explanation:
Please, find attached the graph that accompanies this question.
The<em> melting</em> proces is the change from solid phase to liquid phase. It is represented with the lower flat line with the symbol ΔHfus over it.
The line is flat because the temperature remains constant during this process. Thus, you know the option "C) As the temperature increases during melting, the kinetic energy also increases" is FALSE.
What happens during this process is:
- Most of the energy received by the particles from heating, during the melting process, goes to overcome the intermolecular bonds between the particles. This results in increasing the distance between the particles, so the internal potential energy increases. This is what the option <em>"B) Absorbed energy results in the change in potential energy" correctly describes.</em> Hence, option B) is TRUE.
Althoug most of the heat energy received is transformed into potential energy, yet a small part of the heat energy increases a bit the kinetic energy of the particles, because the particles will vibrate faster around their relatively fixed positions. Hence, the option "<em>A) The kinetic energy of the particles remains unchanged</em>" is FALSE.
As for option D) it is not reasonable at all: none chemical or physical priciple can be used to state that <em>the kinetic energy decreases as the particles move farther apart</em>. Thus, this is FALSE.
They were able to find the orbit of a comet and predict the year of its return.
Answer:
We must duplicate the length of the rope (R'=2R) to get

Explanation:
The equation of the centripetal force is given by:


Where:
R is the length of the rope
m is the mass of the object
v is the speed of the object
If we want to reduce the centripetal force in half, we can duplicate the length of the rope (R'=2R), which means:



I hope it helps you!
Answer:
14.47 m/s
Explanation:
The momentum must be preserved before and after the collision:
The total momentum before the collision

where
are the masses of the car moving south and north, respectively, before the collision.
is the velocity of the car moving South. We take the velocity to the North as the positive direction
The total momentum after the collision

where V = 5.22m/s is the velocity of both cars after the collision
We can equalize the 2 equations and plug in the numbers:





The work needed to pump the water would have the units of Joules or Pa*m^3. From here, this would be a hint that you only multiply the hyraulic pressure and its volume.
Hydraulic pressure = density*gravity*height = 1000*9.8*3.1 = 30,411 Pa
Volume = 21*14*3.1 = 911.4 m^3
Work = 30,411*911.4 = 27,716,585.4 J = 27.72 MJ