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3 years ago

Describe how excavations are done.

Physics

1 answer:

Mazyrski [523]3 years ago

4 0

Answer:

It includes earthwork, trenching, wall shafts, tunneling and underground

Explanation:

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If 20 beats are produced within one second, which of the following frequencies could possibly be held by two sound waves traveli

NeTakaya

Answer:

D. 22 Hz and 42 Hz

Explanation:

When two waves with different frequency travelling in the same medium meet each other, they produce an interference pattern called beat.
The frequency of the beat produced is equivalent to the difference between the individual frequencies of the two waves involved.
Therefore; in this case since the frequency of the beat is 20 Hz, that is from 20 beats per second.
We need to find a pair from the choices whose frequency difference is 20 Hz.
This happens to be choice D. 22 Hz and 42 Hz, that is 42 Hz - 22 Hz = 20 Hz

8 0

3 years ago

Read 2 more answers

A string of length 100 cm is held fixed at both ends and vibrates in a standing wave pattern. The wavelengths of the constituent

azamat

The wavelengths of the constituent travelling waves CANNOT be 400 cm.

The given parameters:

Length of the string, L = 100 cm

The wavelengths of the constituent travelling waves is calculated as follows;

$L = \frac{n \lambda}{2} \\\\n\lambda = 2L\\\\\lambda = \frac{2L}{n}$

for first mode: n = 1

$\lambda = \frac{2\times 100 \ cm}{1} \\\\\lambda = 200 \ cm$

for second mode: n = 2

$\lambda = \frac{2L}{2} = L = 100 \ cm$

For the third mode: n = 3

$\lambda = \frac{2L}{3} \\\\\lambda = \frac{2 \times 100}{3} = 67 \ cm$

For fourth mode: n = 4

$\lambda = \frac{2L}{4} \\\\\lambda = \frac{2 \times 100}{4} = 50 \ cm$

Thus, we can conclude that, the wavelengths of the constituent travelling waves CANNOT be 400 cm.

The complete question is below:

A string of length 100 cm is held fixed at both ends and vibrates in a standing wave pattern. The wavelengths of the constituent travelling waves CANNOT be:

A. 400 cm

B. 200 cm

C. 100 cm

D. 67 cm

E. 50 cm

Learn more about wavelengths of travelling waves here: brainly.com/question/19249186

5 0

3 years ago

2 (a) A plane from airport A flies 280 km to the east to airport B. The plane then travelled north to airport C, 190 km away. (i

Mekhanik [1.2K]

Answer:

See below

Explanation:

See attached diagram

280 km east then 190 km north

Use Pythagorean theorem to find the resultant displacement

d^2 = 280^2 + 190^2

d = 338.4 km

Angle will be arctan ( 190/280) = 34.16 °

4 0

2 years ago

Twin brothers, Andy and Brian, can mow their grandparents lawn together in 1212 minutes. Brian would mow the lawn by himself

Karo-lina-s [1.5K]

Answer:

It will take Andy 1.198minutes to mow the lawn and it will take Brian 1,209.98minutes to mow the same lawn.

Step-by-step explanation:

Using the simultaneous equation concept, let A denote Andy and B be Brian

Andy and Brian can mow the lawn for 1212minutes i.e A+B = 1212..eqn 1

If Brian would mow the lawn by himself in 1010 minutes more than it would take Andy, this means B=1010A...eqn 2.

Substituting eqn 2 into eqn 1

Equation 1 becomes

A+1010A=1212

1011A=1212

A=1212/1011

A=1.198

B = 1010×1.198

B=1,209.98

Therefore, It will take Andy 1.198minutes to mow the lawn and it will take Brian 1,209.98minutes to mow the same lawn.

6 0

3 years ago

A graph can be described as:

pantera1 [17]

D all of the above

....

6 0

3 years ago