Answer:
The correct answer is - option A. The mashed potatoes will transfer heat into the gravy.
Explanation:
In this case, where Yamel heats the mashed potatoes but forgets to heat the gravy and put the cold gravy on the hot mashed potatoes. Heat always transfers from the high-temperature object to the low-temperature object. So the hot mashed potatoes will transfer the heat to the gravy according to option A. Cold is not a form of heat but the condition of absence of heat or very low temperature.
Thus, the correct answer is - option A. The mashed potatoes will transfer heat into the gravy.
Answer: An iron atom emits particles when it is struck by light (by the photoelectric effect)
Explanation:
The first atomic model was the one proposed by Jhon Dalton, according to which it is postulated that:
"Matter is made up of indivisible, indestructible and extremely small particles called atoms."
That is, <u>the atom is a solid and indivisible mass.
</u>
However, the fenomenom by which an iron atom emits particles when it is struck by light (known as the photoelectric effect) can not be explaind by this<u> indivisible atom</u> model.
To understand it better:
The <u>photoelectric effect</u> consists of the emission of electrons (electric current) that occurs when light falls on a metal surface under certain conditions.
This is possible by considering light as a stream of photons, where each of them has energy. <u>This energy is be able to pull an electron out of the crystalline lattice of the metal and communicate, in addition, a kinetic energy. </u>This means the atom is not indivisible, but it is a composition of different particles.
In fact, currently it is known that each atom is composed of a nucleus and one or more electrons attached to the nucleus, which is composed of one or more protons and typically a similar number of neutrons.
Answer:
Workdone = 600 Kilojoules
Explanation:
Given the following data:
Time = 8 seconds
Power = 75,000 Watts
Distance = 58 m
To find the work done;
Power can be defined as the energy required to do work per unit time.
Mathematically, it is given by the formula;
Thus, work done is given by the formula;
Workdone = power * time
Workdone = 75000 * 8
Workdone = 600,000 = 600 KJ
To solve this problem we will apply the concepts related to the momentum.
This is defined as the product between the change in velocity and the mass of the object, that is
Where,
m = mass
Final velocity
Initial velocity
Our values are given as,
m = 14kg
= 11m/s
<em>the negative Symbol implies that the direction is opposite to the initial one and therefore there is also a change in the sense of magnitude</em>
The negative symbol indicates that the momentum has a direction opposite to that of the initial velocity. Or failing that, it has the same direction of the final speed
Answer:
Since the bar cannot translate, linear momentum is not conserved
Explanation:
By conservation of the angular momentum:
Lo = Lf
where
; 
; d=1.6m; L=3m; 
; 
; 
Solving for 
:
Replacing the values we get:
Since the bar can only rotate (it canno translate), only angular momentum is conserved.
