Which statement is true about how early humans met their needs?

The heater element of a 120 V toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. The resistivity of nichrome

Ksenya-84 [330]

Answer:

The power drawn by the toaster is closest to:

(A) 370 W

Explanation:

First we calculate the resistance of the nichrome wire (R).

$R=\frac{pL}{A} =\frac{pL}{\pi r^{2} } \\$

Where radious (r), resistance coefficient (p), and Length (L)

$r=\frac{0.48}{2} 10^{-3} m\\\\L=5.4 m\\p=1.3*10^{-3}\varOmega \\\\\\Replacing:\\\\R=\frac{1.3(10)^{-6} *5.4}{\pi* 0.24^{2} (10)^{-6}} =38.7940$

After replace the value in the ohm law power formula to obtain the power consumed:

$P=\frac{V^2}{R} =\frac{120^2}{38.7940} =371.191 Watts$

7 0

3 years ago

A tire measures 20 inches in diameter. How many revolutions will the tire have completed when it has traveled 100 yards? Express

Soloha48 [4]

<h2>Number of revolutions required to travel 100 yards is 57.</h2>

Explanation:

Diameter of tire,D = 20 inches

Perimeter of tire = πD

Perimeter of tire = π x 20 = 62.8 inches

Distance traveled = 100 yards

1 yard = 36 inches

Distance traveled = 100 x 36 = 3600 inches

In one revolution it travels 62.8 inches.

$\texttt{No of revolutions = }\frac{3600}{62.8}\\\\\texttt{No of revolutions = }57.32\\\\\texttt{No of revolutions = }57$

Number of revolutions required to travel 100 yards is 57.

8 0

3 years ago

A spring on a horizontal surface can be stretched and held 0.2 m from its equilibrium position with a force of 16 N. a. How much

nekit [7.7K]

Answer:

a $W_{3.5} = 490 \ J$

b $W_{2.5} = 250 \ J$

Explanation:

Generally the force constant is mathematically represented as

$k = \frac{F}{x}$

substituting values given in the question

=> $k = \frac{16}{0.2}$

=> $k = 80 \ N /m$

Generally the workdone in stretching the spring 3.5 m is mathematically represented as

$W_{3.5} = \frac{1}{2} * k * (3.5)^2$

=> $W_{3.5} = \frac{1}{2} * 80 * (3.5)^2$

=> $W_{3.5} = 490 \ J$

Generally the workdone in compressing the spring 2.5 m is mathematically represented as

$W_{2.5} = \frac{1}{2} * k * (2.5)^2$

=> $W_{2.5} = \frac{1}{2} * 80 * (2.5)^2$

=> $W_{2.5} = 250 \ J$

5 0

2 years ago

Which trophic level has the least available energy in kilojoules in this food web?

insens350 [35]

The highest trophic level has the least available energy in kilojoules.

Even though the food web is not shown in the question, but we know that energy decreases steadily as it is passed on from one trophic level to the next according to the second law of thermodynamics.

Energy enters into the system from the sun. The primary producers utilize this energy to produce food. As plants are eaten by animals, this energy is transferred along the food web an diminishes at each higher trophic level.

At the highest trophic level, the the least available energy in kilojoules in this food web is found.

Learn more: brainly.com/question/2233704

7 0

2 years ago

Im bad at work problems can any one help with this problem ?

lyudmila [28]

We will put the number of trips in the first column, the miles driven in the second column and gallons of fuel used in the third column.

8 7,680 1,010
7 9,940 1,330
12 14,640 1,790
12 13,920 2,050

4 0

3 years ago