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3 years ago

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A man wishes to row the shortest possible distance from north to south across a river which is flowing at 2 km/hr from the east.

He can row at 4 km/hr. (a) In which direction should he steer

1 answer:

sweet-ann [11.9K]3 years ago

8 0

From the diagram we have that

$sin\theta = \frac{2}{4}$

$\theta = sin^{-1} (\frac{1}{2})$

$\theta = 30\°$

Therefore the direction is 30° from east of south

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A thin soap bubble of index of refraction 1.33 is viewed with light of wavelength 550.0nm and appears very bright. Predict a pos

faust18 [17]

Answer:

The possible thickness of the soap bubble = $1.034\times 10^{-7}\ m.$

Explanation:

<u>Given:</u>

Refractive index of the soap bubble, $\mu=1.33.$
Wavelength of the light taken, $\lambda = 550.0\ nm = 550.0\times 10^{-9}\ m.$

Let the thickness of the soap bubble be $t$ .

It is given that the soap bubble appears very bright, it means, there is a constructive interference takes place.

For the constructive interference of light through a thin film ( soap bubble), the condition of constructive interference is given as:

$2\mu t=\left ( m+\dfrac 12 \right )\lambda.$

where $m$ is the order of constructive interference.

Since the soap bubble is appearing very bright, the order should be 0, as $0^{th}$ order interference has maximum intensity.

Thus,

$2\mu t=\left (0+\dfrac 12\right )\lambda\\t=\dfrac{\lambda}{4\mu}\\\ \ = \dfrac{550\times 10^{-9}}{4\times 1.33}\\\ \ = 1.034\times 10^{-7}\ m.$

It is the possible thickness of the soap bubble.

6 0

3 years ago

Explain what happens during stages A and B.

fgiga [73]

Is there a picture?

3 0

2 years ago

A student observes rock layers that are folded and appear to be scratched. Select all of the geologic forces that might have cau

mrs_skeptik [129]

Rock layers are folded and appear to be scratched because of the plate tectonics and the glacial advance.

Answer: Option 1 and 2.

<u>Explanation:</u>

Plate tectonics and the glacial advance are the geological phenomenon which have the power to effect the layers of the rock. Because of these, there can be scratches on the layers of the rock and the layers of the rocks can be folded.

The huge mass of ice that is included in the glacier which may be of thickness of three to four kilometers is a lot to scratch the rocks. These glaciers are responsible for moving the rocks from their original position to a new place altogether.

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3 years ago

Some compounds, like carbon dioxide, are gaseous at room temperature, while others are solid at room temperature. Why is this?

Vesnalui [34]

The answer of a & b are force of cohesion and force of adhesion
Of rest two answers I don't know

8 0

3 years ago

Read 2 more answers

An amateur astronomer looks at the moon through a telescope with a 15-cm-diameter objective. What is the minimum separation betw

Lana71 [14]

Answer:

y = 128.0 km

Explanation:

The minimum separation of two objects is determined by Rayleygh's diffraction criterion, which establishes that two bodies are solved if the first minino of diffraction of one coincides with the central maximum of the second, with this criterion the diffraction equation remains

the diffraction equation for the first minimum is

a sin θ = λ

In the case of circular openings, the equation must be solved in polar coordinates, leaving the expression, we use the approximation that the sine of tea is very small.

θ = 1.22 λ / d

d = 15 cm

to find the distance we can use trigonometry

tan θ = y / L

tan θ = sin θ / cos θ = θ

substituting

y / L = λ / d

y = L λ /d

let's calculate

y = 384 10⁸ 500 10⁻⁹ / 0.15

y = 1.28 10⁵ m

Let's reduce to km

y = 1.28 10⁵ m (1km / 10³ m)

y = 128.0 km

the correct answer is 120 km away

5 0

3 years ago