Answer
given
Case 1-Speed of car 50 Km/h for 15 min
Case 2-Speed of car 85 Km/h for 19 min
Case 3 - Speed of car 60 km/h for 55 min
lunch break time = 25 min
a) total distance travel
we know,
distance = speed x time
D = 94.42 Km
b)
Answer:
A. Because protons are positively charged and like charges repel
Explanation:
In the nucleus of an atom are subatomic particles as follows: proton and neutron. Protons are positively charged subatomic particles while neutrons are neutrally charged. Following the principle that "like charges repel one another", protons in the nucleus of an atom tend to repel one another.
Hence, the need for neutrons to form a strong force with the self-repelling protons. This bonding between the neutrons and protons help keep the nucleus together. Therefore, protons wouldn’t be able to handle being packed into the nucleus without neutrons because protons are positively charged and like charges repel.
Answer:
The nail penetrates into the frame by 1.875 inches
Explanation:
For an 8d nail, it has a length of 2.5 inches, a diameter of 0.13 inches and a head diameter of 0.28125 inches. 8d nails in buildings are used in attaching studs to wall plate, rafter to top wall plates. It is also used when you need to drive a nail at an angle into a wood member.
Since the depth of an 8d nail is 2.5 inches and the sheathing is nailed on the wood frame, to get how far the point of the nail penetrate into the frame, we subtract the depth of the oriented strand board sheathing from the depth of an 8d nail.
Therefore, how far the point of the nail penetrate into the frame = 2.5 inches - 5/8 inches = (2.5 - 0.625) inches = 1.875 inches.
The nail penetrates into the frame by 1.875 inches
F₁ = c / d²
F₂ = c / (3d)²
F₁/F₂ = 3² = 9
F₂ = 1/9 F₁
<span>In the question,' when you are sitting a few feet from the fire, your skin feels warmed. What form of heat transfer are acting to transfer heat from the fire to your skin, the correct option is A, that is, convection and radiation. Heat transfer is defined as the exchange of thermal energy between physical systems. The rate at which the heat is transfer depends on the temprature of the system and the properties of the intervening medium through which the heat is been transfered. There are three basic modes of heat transfer, these are: conduction, convection and radiation. Conduction is defined as the transfer of heat between two bodies through physical contact. When two bodies which have different temprature come in contact, there will be a transfer of heat energy between them until the two of them have the same temprature. Conduction usually occurs in solids and liquids; it occurs in gases also but it is extremely slow. Convection is the process by which heat is transfer in fluids, that is, liquids and gases. This is how convection operates: when a fluid is heated, it expands and it becomes lighter, this makes it to rise upward and move to the cooler part of the container, as it rises, it will be replaced by the unheated surrounding particles. This cycle continues until heat is evenly distributed all through the fluid. There are two types of convection: natural and forced convection. The heating of the earth surface by the sun ray is an example of natural convection while the air conditioner we use at home operates by mean of forced convection. Both conduction and convection require matter for heat transfer. Radiation is the transfer of heat from one place to another through electromagnetic waves. The hot body transfer heat by emitting electromagnetic waves. The properties of the electromagnetic waves depend on the temperature of the body. The higher the temperature the more intense the rate of emission of radiation. Radiation can occur in all objects and does not require matter for heat transfer. The heat of the sun reaches the earth surface by means of radiation. In the question given, as the air surrounding the fire were heated they rise and were replaced by the unheated air particles. The continuation of this cycle makes the heat energy to be transferred to the objects around. Thus, the heat from the fire was transferred via convection and radiation. </span>