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3 years ago

I'll mark brainliest

Physics

1 answer:

irga5000 [103]3 years ago

7 0

Answer:

A) 35 ft

B) 5 ft

C) Net displacement = distance covered by the dog to retrieve the stick - distance covered before the dog starts chewing the stick

Explanation:

A) Total distance covered by the dog = 20 + 15

= 35 ft

B) Since the other distance covered by the dog before chewing the stick, after the retrieval, was in an opposite direction to the initial direction, then;

total displacement of the dog = 20 - 15

= 5 ft

C) Net displacement = distance covered by the dog to retrieve the stick + distance covered before the dog starts chewing the stick

But, displacement involves a specified direction. The distance covered before the dog starts chewing the stick was in an opposite direction to the initial direction.

Thus,

Net displacement = distance covered by the dog to retrieve the stick - distance covered before the dog starts chewing the stick

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A permeability test was run on a compacted sample of dirty sandy gravel. The sample was 175 mm long and the diameter of the mold

LUCKY_DIMON [66]

Answer:

(a). The coefficient of permeability is $8.6\times10^{-3}\ cm/s$ .

(b). The seepage velocity is 0.0330 cm/s.

(c). The discharge velocity during the test is 0.0187 cm/s.

Explanation:

Given that,

Length = 175 mm

Diameter = 175 mm

Time = 90 sec

Volume= 405 cm³

We need to calculate the discharge

Using formula of discharge

$Q=\dfrac{V}{t}$

Put the value into the formula

$Q=\dfrac{405}{90}$

$Q=4.5\ cm^3/s$

(a). We need to calculate the coefficient of permeability

Using formula of coefficient of permeability

$Q=kiA$

$k=\dfrac{Q}{iA}$

$k=\dfrac{Ql}{Ah}$

Where, Q=discharge

l = length

A = cross section area

h=constant head causing flow

Put the value into the formula

$k=\dfrac{4.5\times175\times10^{-1}}{\dfrac{\pi(175\times10^{-1})^2}{4}\times38}$

$k=8.6\times10^{-3}\ cm/s$

The coefficient of permeability is $8.6\times10^{-3}\ cm/s$ .

(c). We need to calculate the discharge velocity during the test

Using formula of discharge velocity

$v=ki$

$v=\dfrac{kh}{l}$

Put the value into the formula

$v=\dfrac{8.6\times10^{-3}\times38}{17.5}$

$v=0.0187\ cm/s$

The discharge velocity during the test is 0.0187 cm/s.

(b). We need to calculate the volume of solid in the ample

Using formula of volume

$V_{s}=\dfrac{M_{s}}{V_{s}}$

Put the value into the formula

$V_{s}=\dfrac{4950\times10^{-3}}{2710}$

$V_{s}=1826.56\ cm^3$

We need to calculate the volume of the soil specimen

Using formula of volume

$V=A\times L$

Put the value into the formula

$V=\dfrac{\pi(17.5)^2}{4}\times17.5$

$V=4209.24\ cm^3$

We need to calculate the volume of the voids

$V_{v}=V-V_{s}$

Put the value into the formula

$V_{v}=4209.24-1826.56$

$V_{v}=2382.68\ cm^3$

We need to calculate the seepage velocity

Using formula of velocity

$Av=A_{v}v_{s}$

$v_{s}=\dfrac{Av}{A_{v}}$

$v_{s}=\dfrac{V}{V_{v}}\times v$

Put the value into the formula

$v_{s}=\dfrac{4209.24}{2382.68}\times0.0187$

$v_{s}=0.0330\ cm/s$

The seepage velocity is 0.0330 cm/s.

Hence, (a). The coefficient of permeability is $8.6\times10^{-3}\ cm/s$ .

(b). The seepage velocity is 0.0330 cm/s.

(c). The discharge velocity during the test is 0.0187 cm/s.

8 0

4 years ago

A large power plant generates electricity at 12.0 kV. Its old transformer once converted the voltage to 425 kV. The secondary of

sergij07 [2.7K]

Answer:

a) 1.2

b) 0.833

c) 0.694

Explanation:

a ) The transformer steps up the voltage from 12000 V to 425000 V . Voltage in primary is 12000 V and in the secondary it is 425000 V in old transformer

If n₁ be no of turns in primary coil and n₂ be no of turns in secondary coils

the formula is

n₂ / n₁ = voltage in secondary / voltage in primary

n₂ / n₁ = 425000 / 12000

ratio of turns in old transformer

= 35.42

ratio of turns in new transformer

n₃ / n₁ = 510 / 12 ( n₃ is no of turns in the secondary of new transformer )

= 42.5

T he ratio of turns in the new secondary compared with the old secondary

n₃ / n₂ = 42.5 / 35.42

= 1.2

b ) Current in secondary / current in primary

= turns in primary / turns in secondary

current output ratio of old

= Current in secondary / current in primary

= n₁ / n₂

= 12 / 425

= .0282

current output ratio of new

= Current in secondary / current in primary

= n₁ / n₃

= 12 / 510

= .0235

The ratio of new current output to old output (at 425 kV) for the same power

= .0235 / .0282

= .833

c ) power loss in new

= (current in secondary )² x resistance of secondary

=( .0235 x current in primary )² x R

= 5.52 X 10⁻⁴ X ( current in primary )² x R

power loss in old

= (current in secondary )² x resistance of secondary

=( .0282 x current in primary )² x R

= 7.95 X 10⁻⁴ X ( current in primary )² x R

ratio of new line power loss to old

= 5.52 / 7.95

= .694

3 0

4 years ago

saw5 [17]

U can infer that it’s a graph line

7 0

3 years ago

A ball is dropped from rest from the top of a building of height h. At the same instant, a second ball is projected vertically u

lawyer [7]

Answer:

Find the answer in the explanation

Explanation:

Given that a ball is dropped from rest from the top of a building of height h. At the same instant, a second ball is projected vertically upward from ground level, such that it has zero speed when it reaches the top of the building.

a. When do the two balls pass each other?

The the balls will pass each other before the second ball reach half of the height of the building. Because the velocity of the second ball decreases as it goes upwards while the velocity of the first ball increases as it moves downwards

b. Which ball has greater speed when they are passing?

The first ball of course because the velocity of the second ball decreases as it goes upwards while the velocity of the first ball increases as it moves downwards

c. What is the height of the two balls when they are passing?

Taking the height from the bottom of the building upward

Since the two balls meet at a certain point, they will both have the same height.

7 0

3 years ago

A circuit has a resistance of 4.0 Ohms. What voltage will produce a current of 1.4 Amps in the circuit

enyata [817]

Answer:

5.6 volts

Explanation:

According to Ohm's Law, V = IR

where V = voltage, I = Current and R = resistance

8 0

3 years ago