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4 years ago

I need to know more about science

Physics

1 answer:

Marizza181 [45]4 years ago

4 0

Answer:

The origin of science can be traced back to ancient Egypt and the Mesopotamia from about 3500 to 3000 BC. The achievements of these two civilizations in mathematics, astronomy, and medicine have reached and shaped the Greek natural philosophy in the classical era, and they usually formally try to explain events in the material world with natural causes . After the fall of the Western Roman Empire, in the first few centuries of the Middle Ages (approximately 400-1000 AD), knowledge about the ancient Greeks’ world concepts was gradually forgotten in Western Europe , while in the Muslim world of the Golden Age of Islam Was preserved in. From the 10th century to the 13th century, Western Europe retrieved the writings of ancient Greece and absorbed the research of Islamic scholars. Natural philosophy was revived, and then transformed in the scientific revolution that began in the 16th century The new ideas and discoveries during this period broke away from ancient Greek ideas and traditional methods. The rapid role of scientific method in acquiring knowledge, but the institutionalization and professionalization of science did not begin to take shape until the 19th century

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A cannon with a muzzle speed of 1 000 m/s is used to start an avalanche on a mountain slope. The target is 2 000 m from the cann

Nataliya [291]

Answer:

∅ = 89.44°

Explanation:

In situations like this air resistance are usually been neglected thereby making g= 9.81 m/ $s^{2}$

Bring out the given parameters from the question:

Initial Velocity ( $V_{1}$ ) = 1000 m/s

Target distance (d) = 2000 m

Target height (h) = 800 m

Projection angle ∅ = ?

Horizontal distance = $V_{1x}$ tcos ∅ .......................... Equation 1

where $V_{1x}$ = velocity in the X - direction

t = Time taken

Vertical Distance = y = $V_{1y}$ t - $\frac{1}{2}$ g $t^{2}$ ................... Equation 2

Where $V_{1y}$ = Velocity in the Y- direction

t = Time taken

$V_{1y}$ = $V_{1}$ sin∅

Making time (t) subject of the formula in Equation 1

t = d/( $V_{1x}$ cos ∅)

t = $\frac{2000}{1000coso}$ = $\frac{2}{cos0}$ = $\frac{d}{cos o}$ ...................Equation 3

substituting equation 3 into equation 2

Vertical Distance = d = $V_{1y}$ $\frac{d}{cos o}$ - $\frac{1}{2}$ g $\frac{2}{cos0} ^{2}$

Vertical Distance = h = sin∅ $\frac{d}{cos o}$ - $\frac{1}{2}$ g $\frac{2}{cos0} ^{2}$

Vertical Distance = h = dtan∅ - $\frac{1}{2}$ g $\frac{2}{cos0} ^{2}$

Applying geometry

$\frac{1}{cos o}$ = $tan^{2} o$ + 1

Vertical Distance = h = d tan∅ - 2 g ( $tan^{2} o$ + 1)

substituting the given parameters

800 = 2000 tan ∅ - 2 (9.81)( $tan^{2} o$ + 1)

800 = 2000 tan ∅ - 19.6( $tan^{2} o$ + 1) Equation 4

Replacing tan ∅ = Q .....................Equation 5

In order to get a quadratic equation that can be easily solve.

800 = 2000 Q - 19.6 $Q^{2}$ + 19.6

Rearranging 19.6 $Q^{2}$ - 2000 Q + 780.4 = 0

$Q_{1}$ = 101.6291

$Q_{2}$ = 0.411

Inserting the value of Q Into Equation 5

tan ∅ = 101.63 or tan ∅ = 0.4114

Taking the Tan inverse of each value of Q

∅ = 89.44° ∅ = 22.37°

4 0

3 years ago

Two 60 cm parallel disks are separated by 40 cm and are aligned directly on top of each other. Both disks are black surfaces wit

Crazy boy [7]

Answer:

775.48 W

Explanation:

given,

diameter of disk = 0.6 cm

length of the disk = 0.4 m

T₁ = 450 K T₂ = 450 K T₃ = 300 K

$\dfrac{d}{r_1}=\dfrac{0.4}{0.3}$ = 1.33

now,

the value of view factor (F₁₂)corresponding to 1.33

F₁₂ = 0.265

F₁₃ = 1 - 0.265 = 0.735

now,

net rate of radiation heat transfer from the disk to the environment:

$=\dot{Q_{1-3}+Q_{2-3}} = 2 \dot{Q_{1-3}}$

= 2 F₁₃ A₁ σ (T₁⁴ - T₃⁴)

= 2 x 0.735 x π x (0.3)² x (5.67 x 10⁻⁸ W/m²) (450⁴ - 300⁴)

= 775.48 W

Net radiation heat transfer from the disks to the environment = 775.48 W

3 0

4 years ago

The medium at point P will?

Tanya [424]

<h2>Answer: remain stationary</h2>

Stationary waves (so called because they seem to be immobile) occur when two waves interfere with the <u>same frequency, amplitude but with different direction</u>, along a line with a phase difference of half wavelength.

In this kind of waves there are two types of points:

The nodes, which are points that remain motionless or stationary and do not vibrate. They are due to the destructive interference of both waves when they meet.

The antinodes, which are points that vibrate with a maximum vibration amplitude. They are due to the non-destructive interference of both waves.

According to this explanation and comparing it with the description, when this two waves pass through each other, the point P will become a node, hence<u> it will remain stationary</u>.

3 0

3 years ago

In lab you find that a 1-kg rock suspended above water weighs 10 N. When the rock is suspended beneath the surface of the water,

pav-90 [236]

Answer:

a. 2N

b. 12N

c. 20N

Explanation:

Dtaa given,

Weight of rock in air=10N

weight of rock in water =8N

a. When the rock is suspend in water, it will displace some water from thr container since Buoyant force is the acts upward and equals in magnitude to the volume of water displays,

The buoyant force is calculated as 10N-8N=2N

b. The scale reading will be the sum of the buoyant force and the weight of the container

scale reading =10N+2N=12N

c. When the rock rest at the bottom of the container, the weight of the rock(10N) is acting downward and the weight of the container also is acting downward. Hence the sum of the two weight gives the reading on the scale

scale reading=10N+10N=20N

4 0

3 years ago

The primary reason a light bulb emits light is due to

Mashutka [201]

<span>The primary reason a light bulb emits light is due to the heating of the resistance in the filament of the light bulb. In fact, the power dissipated in a resistor is given by
</span> $P=I^2 R$
<span>where I is the current and R the resistance. The larger the resistance or the current in the resistor, the larger the power dissipated. Due to this dissipation of power, the temperature of the filament becomes very high, and the resistance becomes incandescent, emitting light.</span>

5 0

4 years ago

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