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2 years ago

Humans experience the longest visible electromagnetic waves as

Physics

1 answer:

Margarita [4]2 years ago

8 0

Answer:

Red light

Explanation:

The electromagnetic spectrum classifies all the electromagnetic waves according to their wavelength/frequency. In order from shortest to longest wavelength, we have

Gamma rays

X rays

Ultraviolet

Visible light

Infrared

Microwaves

Radio waves

All of these waves are invisible to human eye, except for the "visible light" part of the spectrum. Waves in the visible light part are perceived by human as different colors, depending on their wavelength. More specifically, they appear as follows:

Violet (380-450 nm)

Blue (450-495 nm)

Green (495-570 nm)

Yellow (570-590 nm)

Orange (590-620 nm)

Red (620-750 nm)

So we see that the longest electromagnetic wave in the visible light part of the spectrum corresponds to red light.

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A lamp consumes 1000J of ekectrical energy in 10s. Calculate its power.

Mice21 [21]

You do 1000 divide it by 10 which equals 100 W

4 0

2 years ago

Average speed can be represented by the mathematical expression

nevsk [136]

Average speed is defined as total distance moved in total interval of time

so it is given as

$v_{avg} = \frac{distance}{time}$

now here is we show distance by "d" and time by"t"

then we will have mathematical expression as follows

$v = \frac{d}{t}$

5 0

2 years ago

After you pick up a spare, your bowling ball rolls without slipping back toward the ball rack with a linear speed of 2.85 m/s. T

motikmotik

Answer:

V' = 0.84 m/s

Explanation:

given,

Linear speed of the ball, v = 2.85 m/s

rise of the ball, h = 0.53 m

Linear speed of the ball, v' = ?

rotation kinetic energy of the ball

$KE_r = \dfrac{1}{2}I\omega^2$

I of the moment of inertia of the sphere

$I = \dfrac{2}{5}MR^2$

v = R ω

using conservation of energy

$KE_r = \dfrac{1}{2}( \dfrac{2}{5}MR^2)(\dfrac{V}{R})2$

$KE_r = \dfrac{1}{5}MV^2$

Applying conservation of energy

Initial Linear KE + Initial roational KE = Final Linear KE + Final roational KE + Potential energy

$\dfrac{1}{2}MV^2 + \dfrac{1}{5}MV^2 = \dfrac{1}{2}MV'^2 + \dfrac{1}{5}MV'^2 + M g h$

$0.7 V^2 = 0.7 V'^2 + gh$

$0.7\times 2.85^2 = 0.7\times V'^2 +9.8\times 0.53$

V'² = 0.7025

V' = 0.84 m/s

the linear speed of the ball at the top of ramp is equal to 0.84 m/s

6 0

3 years ago

A 1250 kg car, driving 7.39 m/s, runs into the back of a stationary 5380 kg truck. After the collision, the truck moves forward

Leno4ka [110]

Explanation:

Given that,

Mass of the car, m₁ = 1250 kg

Initial speed of the car, u₁ = 7.39 m/s

Mass of the truck, m₂ = 5380 kg

It is stationary, u₂ = 0

Final speed of the truck, v₂ = 2.3 m/s

Let v₁ is the final velocity of the car. Using the conservation of momentum as :

$m_1u_1+m_2u_2=m_1v_1+m_2v_2$

$1250\times 7.39+5380\times 0=1250\times v_1+5380\times 2.3$

$v_1=-2.5\ m/s$

So, the final velocity of the car is 2.5 m/s but in opposite direction. Hence, this is the required solution.

3 0

3 years ago

Question I. SUHU ULT

Lilit [14]

Answer:

Feathers are great thermal insulators.

Explanation:

Feathers are great thermal insulators. The loose structure of down feathers traps air.

As a result, energy cannot be transmitted easily through down feathers. This means birds are insulated from cold air outside, plus their body heat doesn't escape easily either.

Human beings discovered that down feathers are good for insulation long ago. For example, documents from the 1600s show that Russian merchants sold “bird down" to the Dutch hundreds of years ago.

Today, down is used in all sorts of products, including coats, bedding, and sleeping bags, to help better insulate the user from cold weather. Down can be collected from many different types of birds, but most of today's supply comes from domestic geese.

If you have a down coat or comforter, is it all down? In the United States, laws require that products labeled “100 percent down" contain only down feathers.

If your product is labeled “down," it can contain a mixture of both down feathers and synthetic fibers. Not all down feathers are created equal, though.

Down insulation is rated on a measure called “fill power." The higher the fill power, the more the down insulates.

The highest fill-power rating — 1200 — goes to eiderdown, which comes from the Common Eider duck. Eiderdown tends to be expensive.

3 0

3 years ago