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3 years ago

True or False: A chemical reaction always happens when two substances are combined. (please help fast this is a test)

Physics

2 answers:

mina [271]3 years ago

8 0

Answer:probably false

Explanation:

Every time you mix two substances it doesn’t mean it’s going to have a reaction, they have to be two substances that don’t combine. I really hope this helps

Makovka662 [10]3 years ago

6 0

Answer:

no not always sometimes they react at all so false I hope I helped :)

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Coherent microwaves of wavelength 5.00 cm enter a tall, narrow window in a building otherwise essentially opaque to the microwav

zzz [600]

The solution for this problem is:

For 1st minimum, let m be equal to 1.

d = slit width

D = screen distance.

Θ = arcsin (m * lambda/ (d))

= 0.13934 rad, 7.9836 deg

y = D*tan (Θ)

y = 6.50 * tan (7.9836)

= 0.91161 m is the distance from the central maximum to the first-order minimum

8 0

3 years ago

What is the gravitational force on a 70kg that is 6.38x10^6m above the earths surface

NARA [144]

Answer:

171.5 N

Explanation:

The gravitational force on an object due to the Earth is given by

$F=mg$

where

m is the mass of the object

g is the acceleration due to gravity

The acceleration due to gravity at a certain height h above the Earth is given by

$g=\frac{GM}{(R+h)^2}$

where:

G is the gravitational constant

$M=5.98\cdot 10^{24} kg$ is the Earth's mass

$R=6.37\cdot 10^6 m$ is the Earth's radius

Here,

$h=6.38\cdot 10^6 m$

So the acceleration due to gravity is

$g=\frac{(6.67\cdot 10^{-11})(5.98\cdot 10^{24})}{(6.37\cdot 10^6 + 6.38\cdot 10^6)^2}=2.45 m/s^2$

We know that the mass of the object is

m = 70 kg

So, the gravitational force on it is

$F=mg=(70)(2.45)=171.5 N$

5 0

3 years ago

How many earths can fit on the moon

liberstina [14]

Hello My Dear Friend!

Do you mean Sun or actually Moon?

If Moon is what you're looking for...then that is absolutely IMPOSSIBLE, due to that the Earth is WAY bigger than the Moon, therefore, not even HALF of the Earth would fit into the Moon since it's too small XD.

But if it's Sun...well then, t<span>he Answer is that it would take </span>1.3 million Earths<span> to fill up the Sun. That's a lot of Earths LOL XD

</span>I Hope my answer has come to your Help. Thank you for posting your question here in $Brainly.$ We hope to answer more of your questions and inquiries soon. Have a nice day ahead! :)

$(Ps. Mark As Brainliest IF Helped!)$

$-TheOneAboveAll :D$

8 0

3 years ago

A student places her 490 g physics book on a frictionless table. She pushes the book against a spring, compressing the spring by

Paul [167]

Answer:

book speed is 3.99 m/s

Explanation:

given data

mass m = 490 g = 0.490 kg

compressing x = 7.10 cm = 0.0710 m

spring constant k = 1550 N/m

to find out

book speed

solution

we know energy is conserve so

we can say

loss in spring energy is equal to gain in kinetic energy

$\frac{1}{2}*k*x^2 = \frac{1}{2}*m*v^2$ ..................1

put here value

$\frac{1}{2}*1550*0.071^2 = \frac{1}{2}*0.490*v^2$

v = 3.99 m/s

so book speed is 3.99 m/s

5 0

3 years ago

An aircraft travels a distance of 50km in a straight line

Juliette [100K]

Answer:

200 m/s

Explanation:

v = distance / time = 50km/250s = 50000m/250s = 200 m/s

6 0

2 years ago