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4 years ago

Most of the mass of the Milky Way exists in the form of A. dust. B. stars. C. dark matter. D. gas.

Physics

1 answer:

OLga [1]4 years ago

5 0

Answer:

C. Dark Matter

Explanation:

Dark matter is estimated to make up 90 percent of the mass of the galaxy.

The dark matter (as astronomers have come to call the invisible material) extends to a distance of at least 200,000 light-years from the center of the Galaxy.

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a person's lung pressure as recorded by a mercury manometer is 90 mm Hg.Express this pressure in SI units

Sidana [21]

Answer:

11970 pa

Explanation:

A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high, and currently defined as exactly 133.322387415 pascals so if 1 mmHg is 133 pa 90mmHg is 11970 aprox

4 0

3 years ago

Can the kinetic energy of an object be negative? Can the potential energy of an object be negative? Can a potential energy funct

IceJOKER [234]

Answer:

Kinetic energy cannot be negative

potential energy is a reference dependent quantity and it can be positive as well as negative both

Since potential energy is defined only for conservative force so it can not be found for friction force

Explanation:

Kinetic energy of an object is given by the formula

$KE = \frac{1}{2}mv^2$

here we know that

m = mass of object that can not be negative

v = speed of the object and since its square is given here so it can not be negative

so Kinetic energy is always positive

potential energy is given as the energy due to the virtue of the position of object

so it is

$\Delta U = -\int F.dr$

so potential energy is a reference dependent quantity and it can be positive as well as negative both

Since potential energy is defined only for conservative force so it can not be found for friction force

5 0

4 years ago

If an object falls for 4 seconds, how fast is it going when it hits the ground?

MArishka [77]

Acceleration due to gravity is about 9.8 m/s²

So after every second, the speed increase by 9.8 m/s

After 1 second, the object would fall at a speed of 9.8 m/s

After 2 seconds the object would fall at a speed of 19.6 m/s

So after 4 seconds, the object is going to be at a speed of:

9.8 x 4 = 39.2 m/s

-------------------------------------------------

<u>Answer</u>

39.2 m/s

3 0

4 years ago

Astronaut Mark Kelly and his crew traveled to the International Space Station in the space shuttle. The shuttle burned off all r

Nitella [24]

A couple of things, if the shuttle burned all of it's fuel before entering Earth's atmosphere then that means that the shuttle was accelerating towards Earth until it ran out of fuel. At that point, there is little to no air resistance (friction) by the lack of an atmosphere so it keeps accelerating due to Earth's gravitational force. The closer the shuttle gets to Earth the stronger the gravitational pull the shuttle experiences. Note that, once the shuttle reaches Earth's atmosphere it will cause significant amount of friction and thus will cause the shuttle to slow down.

6 0

4 years ago

Read 2 more answers

Mass refers to the gravitational force on the matter in contact with the surface of a planet

Arte-miy333 [17]

Answer: Yes and no.

Explanation: Mass is the amount of matter in an object, whereas weight is the force exerted on an object by gravity. Objects on the surface of the earth have weight, although sometimes the weight is difficult to measure.

8 0

4 years ago