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3 years ago

When an object moves, stops moving, changes speed, or changes direction, how do scientists describe that condition?

1 answer:

8 0

Drop "moves" from the list for a moment.

You can also drop "stops moving", because that's included in "changes speed"
(from something to zero).

When an object changes speed or changes direction, that's called "acceleration".

I dropped the first one from the list, because an object can be moving,
and as long as it's speed is constant and it's moving in a straight line,
there's no acceleration.

I think you meant to say "starts moving". That's a change of speed (from zero
to something), so it's also acceleration.

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When something is hit harder how does the transverse wave change?

Flura [38]

When something is hit harder just like when sound is turned up the waves become higher and more frequent like a zig zag more so then wavy.

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2 years ago

Which of the following is a physical change?

gladu [14]

The answer would be A

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3 years ago

Read 2 more answers

A visible light has a wavelength of 727.3 nm. Determine its frequency, energy per photon, and color.

Snezhnost [94]

Answer:

$f=4.12\times 10^{14}\ Hz$ and $E=2.73\times 10^{-19}\ J$

Explanation:

The wavelength of a visible light is 727.3 nm.

$727.3\ nm=727.3 \times 10^{-9}\ m$

The formula is as follows :

$c=f\lambda$

f is the frequency of the visible light

$f=\dfrac{c}{\lambda}\\\\f=\dfrac{3\times 10^8}{727.3 \times 10^{-9}}\\\\f=4.12\times 10^{14}\ Hz$

Energy of a photon is given by :

E = hf, h is Planck's constant

$E=6.63\times 10^{-34}\times 4.12\times 10^{14}\\\\E=2.73\times 10^{-19}\ J$

Red color has a frequency of $4.12\times 10^{14}\ Hz$ and energy per photon is $2.73\times 10^{-19}\ J$ .

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3 years ago

If the mass of the object is doubled and the speed is halved then kinetic energy will change by a factor of:

madam [21]

Answer:

kinetic energy will change by a factor of 1/2

Option C) 1/2 is the correct answer

Explanation:

Given the data in the question;

we know that;

Kinetic energy = 1/2.mv²

given that mass of the object is doubled; m1 = 2m

speed is halved; v1 = V/2

Now, New kinetic energy will be; 1/2.m1v1²

we substitute

Kinetic Energy = 1/2 × 2m × (v/2)²

Kinetic Energy = 1/2 × 2m × (v²/4)

Kinetic Energy = 1/2 × m × (v²/2)

Kinetic Energy = 1/2 [ 1/2mv² ]

Kinetic Energy = 1/2 [ KE ]

Therefore; kinetic energy will change by a factor of 1/2

Option C) 1/2 is the correct answer

3 0

2 years ago

Which statement best describes perigee?

Alex17521 [72]

Whenever you see "-gee" in the description of a point in an orbit,
you know it's talking about an orbit of the Earth. You see the same
piece of a word in "geology" and "geography". "Geometry" began
as the study of measuring places on the Earth, so that you and your
neighbor could agree on where your field ends and his begins, and
if you wanted to buy part of his field from him, the two of you could
go outside, do some measurements, and agree on what area you're
paying him for.

"Perigee" and "apogee" are the points in the orbit of the Moon, or a
TV satellite, or the International Space Station, where the orbiting body
is nearest or farthest from the Earth. "Perigee" is the lowest/nearest point.
"Apogee" is the highest/farthest point.

If the description has "-helion" in it instead of "-gee", then it's talking about
an orbit around the sun, like points in the Earth's orbit. The "-helion" comes
from the Greek word "Helios" for the Sun.
Earth is at perihelion during the first few days of January, and at aphelion
during the first few days of July. (That's right ... nearest to the sun in January,
and farthest from the sun in July.)

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3 years ago