I NEED HELP PLEASEEE IS MY MIDDLE FINGER FINE

Suppose your surface body temperature averaged 90 degrees F. How much radiant energy in W/m^2 would be emitted from your body?

Debora [2.8K]

$493 \; \text{W}\cdot \text{m}^{-2}$ .

<h3>Explanation</h3>

The Stefan-Boltzmann Law gives the energy radiation per unit area of a black body:

$\dfrac{P}{A} = \sigma \cdot T^{4}$

where,

$P$ the total power emitted,
$A$ the surface area of the body,
$\sigma$ the Stefan-Boltzmann Constant, and
$T$ the temperature of the body in degrees Kelvins.

$\sigma = 5.67 \times 10^{-8} \;\text{W}\cdot \text{m}^{-2} \cdot \text{K}^{-4}$ .

$T = 90 \; \textdegree{}\text{F} = (\dfrac{5}{9} \cdot (90-32) + 273.15) \; \text{K} = 305.372 \; \text{K}$ .

$\dfrac{P}{A} = \sigma \cdot T^{4} = 5.67 \times 10^{-8} \times 305.372^{4} = 493\; \text{W}\cdot \text{m}^{-2}$ .

Keep as many significant figures in $T$ as possible. The error will be large when $T$ is raised to the power of four. Also, the real value will be much smaller than $493\; \text{W}\cdot \text{m}^{-2}$ since the emittance of a human body is much smaller than assumed.

5 0

2 years ago

Alexandra is attempting to drag her 32.6 kg golden retriever across the wooden floor by applying a horizontal force. What force

vichka [17]

Answer:

230.26 N

Explanation:

Since the speed is constant, acceleration is zero hence the net force will be given by the product of mass, coefficient of friction and acceleration due to gravity

F=0.72*32.6*9.81=230.26 N

7 0

2 years ago

Why do the noble gases and some other elements on the right side of the periodic table occur as gases instead of solids as do th

mash [69]

Explanation:

The left side of the periodic table has elements that have less number of electrons in the valence shell.

These elements loose electrons easily.These elements appear as metals or metalloids in nature.These are hard solids.Their inter molecular forces are very strong.

The right side of the periodic table has elements that have more number of electrons in the valence shell.

These elements gain electrons easily.These elements appear as non metals most of which are gases.Their inter molecular forces are weak.

8 0

2 years ago

7. Sketch a labeled history graph of a vibrating particle. Be sure to label the axis of the graph correctly, and point out

nikklg [1K]

Heyyyyyyyyyyyyyyyyyyyy

4 0

2 years ago

Which, if any, of the following statements about electric field lines is/are true? A.The electric field is always perpendicular

jonny [76]

The electric field is always perpendicular to the surface outside of a conductor. TRUE

 If an electron were placed on an electric field line, it would move in a direction perpendicular to the field. FALSE, it would move in an anti-parallel direction because its charge is negative 

Electric field lines originate on positive charge and terminate on negative charge. TRUE ; but they can also go to infinity 

It is possible for two electric field lines to cross each other.
 Usually FALSE; though technically possible at special points where field is zero. 

If an electron and a positron were in the presence of a very strong electric field, they would move away from each other.
 TRUE; one is positive, and one is negative. If the field is strong enough, the action of the field will overcome the mutual attraction between them 

It is not possible for the electric field to ever be zero. FALSE: it IS possible, inside a conductor for instance

If a proton were placed on an electric field line, it would move in a direction anti-parallel to the field.
 FALSE: being positive, it would move in the SAME direction as the fieldic

8 0

2 years ago