Do any of the atom diagrams below represent atoms of the same element?

9) What would be the weight of a 59.1-kg astronaut on a planet with the same density as Earth and having twice Earth's radius?

Hunter-Best [27]

The weight of the astronaut is given by
$W=mg$
where m=59.1 kg is his mass and $g=9.81~m/s^2$ is the gravitational acceleration on Earth.

To solve the problem, we must find the value of g on the new planet. g is given by
$g= \frac{GM}{r^2}$
where G is the gravitational constant, M the mass of the planet and r its radius.
The mass of the planet can be written as
$M=dV$
where d is the density and V the volume.
We can assume that the planet is a sphere, therefore the volume is proportional to $r^3$ :
$V= \frac{4}{3}\pi r^3$
and we can write the mass as
$M= \frac{4}{3} \pi d r^3$
and then, g becomes
$g= \frac{GM}{r^2}= \frac{4}{3} \frac{G \pi d r^3}{r^2}= \frac{4}{3} G \pi d r$
So, in the end g is proportional to the radius of the planet, r (because the density of the new planet d is the same as the Earth's one. If the radius of the new planet is twice the Earth's radius, g will be twice the value of g on Earth:
$g_{new}=2g=2\cdot9.81~m/s^2=19.62~m/s^2$
And since the mass of the astronaut is always the same, the weight on the new planet will be twice the weight on Earth:
$W_{new}=mg_{new}=2mg=1159~N$

5 0

3 years ago

A sound wave travels at 379 m/sec and has a wavelength of 8 meters. Calculate its frequency and period.

olga nikolaevna [1]

$\qquad\qquad\huge\underline{{\sf Answer}}$

Wavelength, Wavespeed and frequency depends on each other in the following way :

$\qquad \sf \dashrightarrow \: frequency = \dfrac{wave \: \: velocity}{wavelength}$

$\qquad \sf \dashrightarrow \: f = \dfrac{389}{8}$

$\qquad \sf \dashrightarrow \: f \approx 48.62 \: \: hertz$

And we know the Reciprocal relationship between frequency and period ~

So, let's find it's period •

$\sf{\qquad \sf \dashrightarrow \: t = \dfrac{8}{389}}$

$\sf{\qquad \sf \dashrightarrow \: t \approx 0.02 sec }$

6 0

2 years ago

Answer please help me

aksik [14]

Answer:

It is showing the wavelength.

Explanation: Hope it helps you:)))

have a good day

7 0

2 years ago

Earth’s largest ecosystems, biomes, are defined primarily by:

Darina [25.2K]

Answer: e. All of the above.

Explanation:

Rainfall, temperature, seasonal variability are the important factors which determines the type of vegetation will grow in a biome, the type of animals will adapt and survive. Also these factors also determine the fact that type of landforms will form over a region. These factors are necessary for the development of the biodiversity. A biodiversity can be define as the variability and variety of life forms that can be found in the ecosystem or biome.

5 0

4 years ago

1. An electric iron has a rating of 750W, 220V. Calculate:

horrorfan [7]

The equation for electrical power isP=VIwhere V is the voltage and I is the current. This can be rearranged to solve for I in 6(a). 6(b) can be solved with Ohm's LawV=IRor if you'd like, from power, after substituting Ohm's law in for IP=V2R For 7, realize that because they are in parallel, their voltages are the same. We can find the resistance of each lamp fromP=V2RThen the equivalent resistance as1R∗=1R1+1R2Then the total power asPt=V2R∗However, this will reveal that (with a bit of algebra)Pt=P1+P2 For 8, again the resistance can be found asP=V2RThe energy usage is simplyE=P⋅t

6 0

3 years ago