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defon
3 years ago
13

Dinosaurs emerged during what time period

Physics
1 answer:
swat323 years ago
6 0
Dinosaurs lived between 230 and 65 million years ago, in a time known as the Mesozoic Era<span>. This was many millions of years before the first modern humans, Homo sapiens, appeared. </span>
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Waves that move the particles of the medium parallel to the direction in which the waves are traveling are called
Nikolay [14]

1. a. longitudinal waves.

There are two types of waves:

- Transverse waves: in transverse waves, the oscillations of the wave occur in a direction perpendicular to the direction of propagation of the wave

- Longitudinal waves: in longitudinal waves, the oscillations of the waves occur parallel to the direction in which the waves are travelling.

So, these types of waves are called longitudinal waves.


2. d. a medium

There are two types of waves:

- Electromagnetic waves: these waves are produced by the oscillations of electric and magnetic field, and they can travel both in a medium and also in a vacuum (they do not need a medium to propagate)

- Mechanical waves: these waves are produced by the oscillations of the particles in a medium, so they need a medium to propagate - therefore, the correct choice is d. a medium


3. a. AM/FM radio

Analogue signals consist of continuous signals, which vary in a continuous range of values. On the contrary, digital signals consist of discrete signals, which can assume only some discrete values. For AM and FM radios, signals are transmitted by using analogue signals.

5 0
3 years ago
 How many centimeters are there in meter? b. 10 c. d 1000 e. 10000 100 2. A centimeter is equal to 1 inch b.½inch C 1/2.54 inch
astra-53 [7]

Answer:

a) There are 100 centimeters in 1 meter.

b) \texttt{A cm is equal to }\frac{1}{2.54}\texttt{ inch}

Explanation:

a) We have the conversion

         1 m = 100 cm

   So there are 100 centimeters in 1 meter.

b) 1 inch = 2.54 cm

    1cm=\frac{1}{2.54}inch

   \texttt{A cm is equal to }\frac{1}{2.54}\texttt{ inch}

8 0
3 years ago
2. A woman prevents a 3kg brick from falling by pressing it against a vertical wall. The coefficient of friction
Anettt [7]
<h3>Answer:</h3>

49 N

<h3>Explanation:</h3>

<u>We are given;</u>

  • Mass of the brick as 3 kg
  • The coefficient of friction as 0.6

We are required to determine the force that must be applied by the woman so the brick does not fall.

  • We need to importantly note that;
  • For the brick not to fall the, the force due to gravity is equal to the friction force acting on the brick.
  • That is; Friction force = Mg

But; Friction force = μ F

Therefore;

μ F = mg

0.6 F = 3 × 9.8

0.6 F = 29.4

      F = 49 N

Therefore, she must use a force of 49 N

6 0
3 years ago
Iron-rich minerals in rock pointed in one direction and then switched to the exact opposite direction. This supports what idea?
NISA [10]
Iron rich minerals in rock pointed in one direction the switch to the exact opposite direction. I'd say that what supports this idea is that Earth's magnetic field goes through pole reversals.<span>
</span>
4 0
3 years ago
Read 2 more answers
The pathologic changes that occur in the development of coronary atherosclerotic lesions include call damage resulting from whic
ale4655 [162]

Answer:

3 effect of oxidized lipids

4 an inflammatory response

5 the formation of plaques

Explanation:

Destruction of cells due to oxidation of lipids whereby free radicals steal electrons in cell membrane.

This occurs when tissues get injured by trauma, bacteria or toxins, thereby causing damages cells to release chemicals like histamine, brakykinn that cause vessels to leak fluid into the injured tissues causing swelling.

-plaques are regions of destroyed cells which are visible structures formed inside a cell culture.

4 0
3 years ago
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