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2 years ago

A cat runs at 2 m/s for 3 s and then slows to a stop with an acceleration of 0.80 m/s2. What is

Physics

1 answer:

sp2606 [1]2 years ago

7 0

Answer:

see that the correct one is B

Explanation:

To solve this exercise let us use the kinematic relations

v² = v₀² - 2 a x

as they indicate that the car stops, therefore the final speed is yield v = 0

x = v₀² / 2a

let's calculate

x = 2²/(2 0.8)

x = 2.5 m / s²

When reviewing the answers we see that the correct one is B

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Do 3-7 for me? It is science and i hate doing science hw.

shtirl [24]

I can't bear to make you handle anything that makes you so uncomfortable. Please ask your Science teacher to contact me directly for the answers.

5 0

3 years ago

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

3 years ago

Which statement correctly describes sound waves

Alexxandr [17]

Answer:

Sound waves are longitudinal waves

Explanation:

Sound waves are the longitudinal waves. In longitudinal waves, the particles of the wave move parallel to the direction of propagation of waves.

It moves in the form of compression and rarefaction. When the particles are compact in a space the compression occurs while when they far apart form each other rarefaction occurs.

3 0

3 years ago

A force of 120 N is exerted on a 40 kg container which sits on a floor. If the frictional force between floor and container is 8

harkovskaia [24]

Answer:

Magnitude is 144N .

Explanation:

a²+b²=c²

120N²+80N²=c²

14400+6400=c²

$\sqrt{20800} = \sqrt{c} ^{2}$

144N=c

7 0

2 years ago

What is the second law of thermodynamics

andriy [413]

It states that the total entropy of an isolated system can never decrease over time

5 0

3 years ago