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4 years ago

why Galileo's thought experiment about the ball rolling forever on a level surface could only be a thought experiment.

1 answer:

8 0

Because in reality there are frictional forces acting on the ball, against the direction of its motion. In fact, because of the friction between the ball and the surface, the ball loses little by little its energy, so its velocity decreases and eventually it stops.
In an ideal world with no friction, there would be no forces acting on the ball, so its energy must be conserved and this means that the ball would continue its motion forever.

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What three sprites are needed to create the Space Invaders game that was discussed in the unit? spaceship, laser, enemy gnome, a

Lilit [14]

Answer: anlien, enemy gnome, spaceship

Explanation:

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2 years ago

The company where you work has obtained and stored five lasers in a supply room. You have been asked to determine the intensity

VikaD [51]

Answer:

a) I = 5.79 10⁵ W/m² , b) I = 2.58 10² W / m², c) I = 8.03 10³ W / m² , d) I = 5.3 10⁶ W / m², e) I = 9 10¹ W / m² , f) D> A> C> B> E

Explanation:

The intensity is defined as the power per unit area

I = P / A

The area of a circle is

A = π r²

Laser A

Power P = 2.2 W

Diameter d = 2.9 mm = 2.9 10⁻³ m

Let's calculate

Area

A = π d² / 4

A = π (2.2 10⁻³)²/4

A = 3.80 10⁻⁶ m²

Let's calculate the intensity

I = 2.2 / 3.80 10⁻⁶

I = 0.579 10⁶ W / m²

I = 5.79 10⁵ W/m²

Laser B

The electric field is E = 440 V / m

Intensity average is

I = E B / 2 μ₀

The relationship of the fields with the speed of light

E / B = c

The intensity

I = EE / 2 μ₀ c

I = 440² / (2 4π 10⁻⁷ 3 10⁸)

I = 1.936 105/750

I = 2.58 10² W / m²

Laser C

The magnetic field amplitude B = 8.2 10⁻⁶ T

I = c / 2μ₀ B²

I = 3 10⁸/2 4π 10⁻⁷ (8.2 10⁻⁶)²

I = 8.03 10³ W / m²

Part D

Diameter d = 1.8 mm = 1.8 10⁻³ m

The radius is r = d / 2 = 0.9 10⁻³ m

The force is F = 9.0 10⁻⁸ N

The radiation pressure is on a reflective surface is

P = 2S / c

I = S =P c / 2

The definition of pressure is

P = F / A

I = F c / 2 A

I = 9.0 10⁻⁸ 3 10⁸ / (2π (0.9 10⁻³)²)

I = 5.3 10⁶ W / m²

Part E

Average energy density

u = 3.0 10⁻⁷ J / m³

I = S = c u

I = 3 10⁸ 3.0 10⁻⁷

I = 9 10¹ W / m²

Part F

Sort in descending order

The order is

D> A> C> B> E

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3 years ago

Which aspect of health is best illustrated by the following example? I work well in a group and

Yuri [45]

Social is the answer

7 0

3 years ago

What is the wavelength in air of red light from a helium neon laser?

Elza [17]

Answer:

632.8 nm is the wavelength (in air) of red light from a helium neon laser.

4 0

2 years ago

Where in the world does average daily temperature exceed the annual temperature range?

padilas [110]

The average daily annual temperature range is exceeded in places such as deserts. Deserts tend to be hotter due to the lack of water contained within them. This means that all of the sun's thermal radiation heats up the ground and air. These factors cause deserts to have above average temperatures.

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3 years ago