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2 years ago

Electric kettle with the resistance of 20-02.is used-to-heat:4 kg of water. If

Physics

1 answer:

jeka942 years ago

5 0

The guy that answered this is fake and he’s doing it for free points so
Just repost it and hope he doesn’t find it

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Future space stations could create an artificial gravity by rotating. Consider a cylindrical space station that rotates with a p

aleksandrvk [35]

Answer:

P = 2 pi R / v period of space station

F / m = v^2 / R centripetal force per unit of mass

So F / m = 4 pi^2 R^2 / (P^2 * R) = 4 pi^2 R / P^2

Also, F / m = 9.8 m/s^2 earth's gravitational attraction

So 9.8 = 4 pi^2 R / P^2 or R = 9.8 P^2 / 4 * pi^2) = 195 m

Or D = 2 R = 390 m the diameter required

8 0

2 years ago

Who was the english thinker who established the three laws of motion?.

Tatiana [17]

Answer:

Isaac Newton

Explanation:

Because i learned this in school

4 0

2 years ago

. Now assuming Anna's far point was found to be 0.9 m (i.e., her eyes can't focus on any object more than 0.9 m away), what powe

Mama L [17]

Answer:1). Distance of far point x=0.9m

Therefore, since the image is virtual

-f=-x = -0.9m

Power of the concave lenses = 1/f = 1/-0.9

= -1.11D

2 ) near point is 21cm = 0.21m

Power = 4-1/near point

= 4/0.21

= 14.2D.

7 0

3 years ago

Why does a hot-air balloon rise?

prohojiy [21]

Answer: The weight of the air displaced by the balloon is less than the volume of the balloon.

Explanation:

A hot air balloon is a cloth wrap that contains several thousand cubic meters of air inside (a large volume of air). The burner heats the liquid propane to a gaseous state to generate a huge flame, which can reach more than 3 meters, thus heating the air mass inside the balloon. In this way, its density is modified with respect to the air that surrounds it, because the hot air is lighter than the outside air (less dense), causing the balloon to rise and float.

Now, if we know that the density of a body $d$ is directly proportional to its mass $m$ and inversely proportional to its volume $V$ :

$d=\frac{m}{V}$

We can deduce that by increasing the volume of the body, its density will decrease.

This is proof of Archimedes' Principle:

A body totally or partially immersed in a fluid at rest, experiences a vertical upward thrust equal to the mass weight of the body volume that is displaced.

In this case the fluid is the air outside. So, the warm air inside the balloon, being less dense, will weigh less than the outside air and therefore will receive an upward pushing force or thrust that will make the balloon ascend.

4 0

2 years ago

Why do intrusive igneous rocks have large crystals?

Aleksandr-060686 [28]

The magma cools very slowly so that the crystals of different minerals have time to grow. The magma molecules in have time to organize themselves into crystal formations before the magma hardens. The naked eye helps the Intrusive rocks that has large crystals be seen.

3 0

2 years ago