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3 years ago

To cook food, a microwave oven converts electrical energy intoenergy A) electromagnetic B) heat C) mechanical D) nuclear

1 answer:

5 0

To cook food, a microwave oven converts electrical energy into electromagnetic energy. (A) Specifically, it pours high-power RADIO waves into the box.

Water molecules and fat molecules resonate (jiggle) with the radio waves, and the heat is generated IN THE FOOD.

I work with microwave radios.

-- To communicate high-speed data over a distance of 5 to 10 miles, we use a radio transmitter with a power output of 0.07 watt .

-- To communicate high-speed data over distances up to 80 miles, we use a radio transmitter with a power output of 1 to 2 watts.

-- To heat up a chunk of leftover meatloaf, a microwave oven pumps radio waves into the box with a power output of 1200 to 1500 watts ! !

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What is your interpretation of 'nothing'? (Talking astrophysics) More answers the better!

Sladkaya [172]

MY personal interpretation of nothing is no atoms or particles of anything. but keep in mind im 11 <span />

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3 years ago

¿Que trabajo realizas cuando subes una bolsa de la compra cuya masa es 4,5 kg desde el suelo hasta una mesa de 90 cm de altura?¿

WITCHER [35]

We are going to do this today

6 0

3 years ago

An airplane touches down on the runway with a speed of 70 m/s2. Determine the airplane after each second of its deceleration.

ivann1987 [24]

<span>vf^2 = vi^2 + 2*a*d
---
vf = velocity final
vi = velocity initial
a = acceleration
d = distance
---
since the airplane is decelerating to zero, vf = 0
---
0 = 55*55 + 2*(-2.5)*d
d = (-55*55)/(2*(-2.5))
d = 605 meters

</span>

5 0

3 years ago

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 <em>per unit area</em> 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.

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3 years ago

Harry and ron set up this experiment with a glider, whose mass they have measured to be 565 g, and seven washers hanging from th

svetlana [45]

Let's call $m=565~g=0.565~kg$ the mass of the glider and $m_w=7\cdot12~g =84~g=0.084~kg$ the total mass of the seven washers hanging from the string.
The net force on the system is given by the weight of the hanging washers:
$F_{net} = m_w g$
For Newton's second law, this net force is equal to the product between the total mass of the system (which is $m+m_w$ ) and the acceleration a:
$F_{net}=(m+m_w)a$
So, if we equalize the two equations, we get
$m_w g = (m+m_w)a$
and from this we can find the acceleration:
$a= \frac{m_w g}{(m+m_w)} = \frac{0.084~kg \cdot 9.81~m/s^2}{(0.565~kg+0.084~kg)}=1.27~m/s^2$

5 0

3 years ago