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3 years ago

The spread of fire from the ground floor to an upper floor of a building primarily due to heat transfer by

1 answer:

4 0

The correct answer is by convection.

In fact, in a fluid (like the air in the room full of fire) the warmer parts of the fluid move upward, replacing the colder parts which go down. For this very same reason, the fire spreads moving toward the upper floors of the bulding.

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How can one explain the fact that nearly all other galaxies appear to be moving farther away from us?

juin [17]

A) the universe is expanding
Every galaxy is moving away from each other - not just us. And the further they are away, the faster they are moving

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2 years ago

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Which region on the map has the highest risk of future landslides?

vladimir2022 [97]

Answer:

Reigon 1

Explanation:

It has the higest rate of landslides currently

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3 years ago

A year 11 pupil with a mass of 55kg swinging back on their chair and falling off it at a speed of 0.6m/s. What is his kinetic en

posledela

Answer:

Uk = 9.9 J

Explanation:

To calculate the kinetic energie (Uk), you can make use of this formula:

Uk = 0.5 * m * v²

given m = 55 kg and v = 0.6 m/s

Substituting in the formula gives:

Uk = 0.5 * 55 * (0.6)²

Uk = 0.5 * 55 * 0.36

Uk = 9.9 J

Extra:

Now let's examine the formula in relation to the SI units. If you understand the following, it will give you great insight in how smart Phisics is inter twained by looking at formulas and their standard units. It will save you time in future to convert formulas, if you use the right standard units.

The formula for kinetic energie is:

Uk = 0.5 * m * v²

Standard SI unit for mass m is kg.

Standard SI unit for speed v is m/s.

So v * v = v² and therefore v² must have the standard SI unit of m²/s².

From the formula, you see that the unit of Uk must be kg*m²/s² and since Uk is normally given in J, these both forms must be the same !

The main unit for Uk is the Joule. Now please see the picture, which shows the relation between the J and other SI units. Please understand that you can construct your 'own' formulas based these units. Now here is the time saver:

Because almost always the right units are given in a question, or because sometimes you can look up a constant in a table with an exotic and seemingly complicated unit, but that says a lot about the formula which must have been some how involved!

By this, I hope you now understand the implication of using the right standard SI units and how that can help you figure out what formula is needed.

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2 years ago

What is meant by the term 'mass movement'?

vitfil [10]

Mass movement is the movement of surface materials caused by gravity. A great example would be a mud slide.

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2 years ago

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What is one fun fact about both rubies and sapphires?

Rufina [12.5K]

Answer:

A ruby is measures a 9 on the Mohs Scale of Hardness, second only to diamond and matched with sapphire. This makes a ruby an extremely hard and durable gemstone.

A sapphire is the birthstone for September. It is also a traditional gift for those celebrating 5th or 45th anniversaries.

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2 years ago

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