Which is a “big idea” for matter and change?

Elan Coil [88]

The answer is D light rays shine on an object which then reflects back to our retina

5 0

3 years ago

imagine that 501 people are present in a movie theater of volume 8.00 x10^3 that is sealed shut so no air can escape. Each perso

Semenov [28]

Answer:

The temperature of air will increase by $\Delta T=41044.967\ K$

Explanation:

Given:

no. of person in a theater, $n=501$

volume of air in the theater, $V=8\times 10^3\ m^3$

rate of heat given off by each person, $P=110\ J.s^{-1}$

duration of movie, $t=2\ hr=7200\ s$

initial pressure in the theater, $p_i=1.01\times 10^5\ Pa$

initial temperature in the theater, $T_i=20+273=293\ K$

specific heat capacity of air at the given conditions, $c=1.0061\ J.kg^{-1}.K^{-1}$

<u>The total quantity of heat released by the total people in the theater during the movie:</u>

$Q=n.P.t$

$Q=501\times 110\times 7200$

$Q=396792000\ J$

<u>Form the relation of heat capacity:</u>

$Q=m.c.\Delta T$

∵ $p_i.V=m.R.T$

$Q=(\frac{p_i.V}{R.T}) \times c\times (T_f-T_i)$

$396792000=(\frac{1.01\times 10^5\times 8\times 10^3}{287\times 293}) \times 1.0061\times (T_f-293)$

$T_f=41337.967\ K$

Change in temperature of air:

$\Delta T=41044.967\ K$

8 0

2 years ago

An ideal gas occupies 0.4 m3 at an absolute pressure of 500 kPa. What is the absolute pressure if the volume changes to 0.9 m3 a

sveticcg [70]

Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

$P_1V_1 = P_2V_2$

Since we are finding the new volume

$V_2 = \frac{P_1V_1}{P_2} \\$

From the question we have

$V_2 = \frac{0.4 \times 500000}{0.9} = \frac{200000}{0.9} \\ = 222222.2222... \\ = 222222$

We have the final answer as

Hope this helps you

5 0

2 years ago

Compare the electric and gravitational force between the electron and the proton in a hydrogen atom. The electric charge of the

zepelin [54]

The gravitational attraction between electron and proton is 10−40 whereas electrostatic force of attraction between a proton and an electron is 10-8.

<h3>What is the gravitational force between electron and proton in a hydrogen atom?</h3>

The gravitational attraction between electron and proton in a hydrogen atom is weaker than the coulomb attraction by a factor of about 10−40 while on the other hand, the electrostatic force of attraction between a proton and an electron in a hydrogen atom is 10- 8 which is 9 times.

The electric charge of the electron and proton are the same i.e. -1.60x10-19C whereas their gravitational force is different due to difference in mass.

So we can conclude that gravitational attraction between electron and proton is 10−40 whereas electrostatic force of attraction between a proton and an electron is 10-8.

Learn more about force here: brainly.com/question/12970081

#SPJ1

7 0

2 years ago

A train is accelerating at a rate of 2 km/hr/s. If its initial velocity is 20 km/hr, what is its velocity after 30 seconds?

Aleksandr [31]

"2 km/hr/s" means that in each second, its engines can increase its speed by 2 km/hr.

If it keeps doing that for 30 seconds, its speed has increased by 60 km/hr.

On top of the initial speed of 20 km/hr, that's 80 km/hr at the end of the 30 seconds.

This whole discussion is of <em>speed</em>, not velocity. Surely, in high school physics,
you've learned the difference by now. There's no information in the question that
says anything about the train's <em>direction</em>, and it was wrong to mention velocity in
the question. This whole thing could have been taking place on a curved section
of track. If that were the case, it would have taken a team of ace engineers, cranking
their Curtas, to describe what was happening to the velocity. Better to just stick with
speed.

4 0

3 years ago