<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>
You need to set their position functions equal to one another and so for the time t when that is true. That is when the tiger and the deer are in the same place meaning the tiger catches the dear
Xdear= 2t+15 deer position function.
(I integrated the velocity function )
To get the Tigers position function you must integrate the acceleration twice. This becomes
Xtiger=t^2
Now t^2=2t+15
Time t is when the tiger catches the deer
t^2-2t-15=0
(t-5)(t+3)=0 factored
t=5s is the answer you use (t=-3 is a meaningless solution)
Using Fleming’s left hand rule,
The magnetic force on the electron will be west. Example: If it is dropped above the equator in Africa, the electron will head towards North America.
Answer:
17.1
Explanation:
The distance ahead, of the deer when it is sighted by the park ranger, d = 20 m
The initial speed with which the ranger was driving, u = 11.4 m/s
The acceleration rate with which the ranger slows down, a = (-)3.80 m/s² (For a vehicle slowing down, the acceleration is negative)
The distance required for the ranger to come to rest, s = Required
The kinematic equation of motion that can be used to find the distance the ranger's vehicle travels before coming to rest (the distance 's'), is given as follows;
v² = u² + 2·a·s
∴ s = (v² - u²)/(2·a)
Where;
v = The final velocity = 0 m/s (the vehicle comes to rest (stops))
Plugging in the values for 'v', 'u', and 'a', gives;
s = (0² - 11.4²)/(2 × -3.8) = 17.1
The distance the required for the ranger's vehicle to com to rest, s = 17.1 (meters).
