Write an equation for the nth term of the arithmetic sequence: 64, 78, 92, 106, ...

#26: Why is spear fishing much more successful for scuba divers than someone spear fishing from above the water? Explain your re

frozen [14]

The water has an irregular surface so if the light rays fall on top then it will reflect oppositely or in some cases may refract, so the fish will seem a bit smaller or further or closer in anyway, example if u put a straw in water it looks bent but is it ? nope. So the main reason is that it refracts which makes the accuracy lesser which make it difficult.

6 0

3 years ago

A radar receiver indicates that a pulse return as an echo in 20 μs after it was sent. How far away is the reflecting object? (c

Assoli18 [71]

A radar receiver indicates that a pulse return as an echo in 20 μs after it was sent. The reflecting object would be 3000 m away .

Phenomenon of hearing back our own sound is called an echo. It is due to successive reflection of sound waves from the surfaces or obstacles of large size. To hear an echo, there must be a time gap of 0.1 second in original sound and the reflected sound.

Given

time = 20 μs = 20 * $10^{-6}$ s

let distance to the reflecting surface be = x

total distance travelled by pulse will be = 2x

speed = 3.0 × $10^{8}$ m/s

distance = speed * time

2x = 3.0 × $10^{8}$ * 20 * $10^{-6}$

x = 3000 m

The reflecting object would be 3000 m away

To learn more about echo here

brainly.com/question/14861578?referrer=searchResults

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5 0

2 years ago

Ron weighs a bottle with a mass of 0.5 kilograms on a spring scale. The spring stretches by 1 centimeter. He then weighs a secon

Yuri [45]

Answer:

1 kg

Explanation:

Applying,

Hook's law,

F = ke................. Equation 1

Where F = force, k = force constant of the spring, e = extension.

But from the question,

The weight of the bottle is the force acting on the spring scale

therefore,

mg = ke............ Equation 2

Where m = mass of the bottle, g = acceleration due to gravity.

make k the subject of the equation

k = mg/e............ Equation 3

Given: m = 0.5 kg, e = 1 cm = 0.01 m

Constant: g = 9.8 m/s²

k = (0.5×9.8)/0.01

k = 490 N/m

If the mass of the second bottle is weighed,

given: e = 2 cm = 0.02 m

subtitute into equation 1

m×9.8 = 490×0.02

9.8m = 9.8

m = 9.8/9.8

m = 1 kg.

Hence the mass of the second bottle is 1 kg

5 0

3 years ago

Two workers are sliding 300 kg crate across the floor. One worker pushes forward on the crate with a force of 400 N while the ot

almond37 [142]

Answer:

The kinetic coefficient of friction of the crate is 0.235.

Explanation:

As a first step, we need to construct a free body diagram for the crate, which is included below as attachment. Let supposed that forces exerted on the crate by both workers are in the positive direction. According to the Newton's First Law, a body is unable to change its state of motion when it is at rest or moves uniformly (at constant velocity). In consequence, magnitud of friction force must be equal to the sum of the two external forces. The equations of equilibrium of the crate are:

$\Sigma F_{x} = P+T-\mu_{k}\cdot N = 0$ (Ec. 1)

$\Sigma F_{y} = N - W = 0$ (Ec. 2)

Where:

$P$ - Pushing force, measured in newtons.

$T$ - Tension, measured in newtons.

$\mu_{k}$ - Coefficient of kinetic friction, dimensionless.

$N$ - Normal force, measured in newtons.

$W$ - Weight of the crate, measured in newtons.

The system of equations is now reduced by algebraic means:

$P+T -\mu_{k}\cdot W = 0$

And we finally clear the coefficient of kinetic friction and apply the definition of weight:

$\mu_{k} =\frac{P+T}{m\cdot g}$

If we know that $P = 400\,N$ , $T = 290\,N$ , $m = 300\,kg$ and $g = 9.807\,\frac{m}{s^{2}}$ , then:

$\mu_{k} = \frac{400\,N+290\,N}{(300\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)}$

$\mu_{k} = 0.235$

The kinetic coefficient of friction of the crate is 0.235.

5 0

3 years ago

Yamel is heating up leftover mashed potatoes from Thanksgiving. She forgot to put gravy on them. So she puts the cold gravy on t

monitta

Answer:

The correct answer is - option A. The mashed potatoes will transfer heat into the gravy.

Explanation:

In this case, where Yamel heats the mashed potatoes but forgets to heat the gravy and put the cold gravy on the hot mashed potatoes. Heat always transfers from the high-temperature object to the low-temperature object. So the hot mashed potatoes will transfer the heat to the gravy according to option A. Cold is not a form of heat but the condition of absence of heat or very low temperature.

Thus, the correct answer is - option A. The mashed potatoes will transfer heat into the gravy.

3 0

3 years ago