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3 years ago

I feel like I’ve been on this physics exam forever… please help . NO LINKS.

Physics

1 answer:

sesenic [268]3 years ago

4 0

Explanation:

my guess is A

emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.

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1. What causes velocity to change?

tresset_1 [31]

The amount of force an object has will change the velocity

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3 years ago

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An incident on route 12 summary?I need to describe what happens in the book in a short summary can anyone help?

Serga [27]

Answer: An Incident on Route 12 is presented here in a high quality paperback edition. This popular classic work by James H. Schmitz is in the English language, and may not include graphics or images from the original edition.

Explanation: I HOPE THAT HELPED

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3 years ago

i wanna learn a little bit of physics so if anyone could teach me a thing or two it would be much appreciated

pentagon [3]

Answer:

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3 years ago

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An archer draws her bow and stores 34.8 J of elastic potential energy in the bow. She releases the 63 g arrow, giving it an init

elena-14-01-66 [18.8K]

Answer:

Approximately $71\%$ .

Explanation:

The formula for the kinetic energy $\rm KE$ of an object is:

$\displaystyle \mathrm{KE} = \frac{1}{2}\, m \cdot v^2$ ,

where

$m$ is the mass of that object, and
$v$ is the speed of that object.

Important: Joule ( $\rm J$ ) is the standard unit for energy. The formula for $\rm KE$ requires two inputs: mass and speed. The standard unit of mass is $\rm kg$ while the standard unit for speed is $\rm m \cdot s^{-1}$ . If both inputs are in standard units, then the output (kinetic energy) will also be in the standard unit (that is: joules,

Convert the unit of the arrow's mass to standard unit:

$m = 63\; \rm g = 0.063\; \rm kg$ .

Initial $\rm KE$ of this arrow:

$\begin{aligned}\mathrm{KE} &= \frac{1}{2} \, m \cdot v^2 \\ &= \frac{1}{2}\times 0.063\; \rm kg \times \left(\rm 28 \; m \cdot s^{-1}\right)^2 \\ &\approx 24.696\; \rm J\end{aligned}$ .

That's the same as the energy output of this bow. Hence, the efficiency of energy transfer will be:

$\displaystyle \frac{24.696\; \rm J}{34.8\; \rm J} \times 100\% \approx 71\%$ .

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3 years ago

What is the speed of a cheetah if it takes 20 sesonds to run 300 m

natta225 [31]

the answer to your question is 15 :)

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3 years ago