What two kinds of motion combine to produce projectile motion?

The process of loosening of soil is called ?

IrinaK [193]

Answer is : a) tilling

3 0

4 years ago

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:

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

8 0

4 years ago

Concerned with citizen complaints of price gouging during past hurricanes, Florida's state government passes a law setting a pri

natta225 [31]

Answer:idk

Explanation:idk

7 0

3 years ago

If you had to explain to a non-scientist why it is that scientists accept the idea that all material things are composed of atom

Taya2010 [7]

Answer:

There are many things that convinced scientists of the existence of atoms, and it has been accepted for at least 100 years now, examples are the macroscopic behaviour of gases, the light emitted by hydrogen lamps, and more recently it has become possible to see individual atoms with the best microscopes!

Explanation:

There are many reasons why people thought that our material world was composed of atoms. One of the most striking reasons why scientists came to believe in atomic theory was how it could explain phenomena like the behaviour of gases, by assuming that gases were composed of a great number of individual particles moving randomly, scientists like Maxwell and Boltzmann developed a theory that could explain the macroscopic behaviour of gases, this theory is called the Kinetic Theory of Gases.

More convincing maybe is how Quantum mechanics can predict phenomena like the atomic emission spectrum of Hydrogen and many molecules and atoms. That the spectra of different elements can be explained by assuming they are made of atoms and using quantum mechanics to predict the frequency at which these atoms will emit or absorb light is a very convincing argument! The Spectrum of hydrogen can be seen with an hydrogen lamp and a prism to separate the different wavelengths.

Moreover, modern electron microscopes can indeed detect single atoms! That means that one can quite literally see single atoms.

Most of the technological development of humanity for the last century wouldn't have been possible without atomic theory, as it underpin our understanding of the physical world.

5 0

4 years ago

What's a proposed set of statements that attempt to explain a natural occurrence?

marta [7]

A proposed set of statements that attempt to explain a natural occurrence is a theory.

7 0

4 years ago