Detailed research on comets indicates that they cannot be older than HOW MANY years.

You are on an interstellar mission from the Earth to the 8,7 light-years distant star Sirius. Your spaceship can travel with 70%

marishachu [46]

Answer:

Time = 12.43 years

Mass = 4.71.43kg

Explanation:

Given the following :

Distance = 8.7 light years

Speed = 70% the speed of light

Diameter = 6m

Lengtg = 25m

Density = 1 hydrogen atom/m^3

Mass of proton(Me) = 1.673x 10^-27

A.) time it takes your spaceship to reach Sirius :

From the relation: Speed = (distance / time)

Time = distance / speed

Time = (70/100) × 1 light year

Distance = 8.7 light years

Time = 8.7 / 0.7 = 12.4285 years

Time = 12.43 years

B.) Mass of inter-stellar gas that collides with the spaceship can be calcuted by finding the product of the surface area of the cylindrical space ship and the mass of proton.

That is ;

surface area * mass of proton

Surface area of a cylinder = 2πrh + πr^2×Me

= 2πrh + Me×πr^2)

=( 2 × 22/7 × 3 × 25) + (22/7 × 3^2 × 1.673 * 10^-27)

= 2× 235.714 + 28.285) × 1.673 * 10^-27

= 471.428 + 47.31 * 10^-27

= 471.428 + 4.73 × 10^-26

= 4.71.43kg approximately

7 0

3 years ago

Which action can be explained by physics?

steposvetlana [31]

Answer:

Actions that underlie mathematical rules, patterns or probability distributions.

For example how fast something falls at any given point or time.

More complex actions, such as human decision making in single individuals would be way too complicated to describe in physical terms.

But note that there can be physical models of such things as traffic when we can assume statistical knowledge of behavior.

Also physical models are used to plan such things as emergency exits in big stadiums, because many thousands of people can be described as particles flowing under a given pressure.

Every time we can gain good statistical knowledge and can therefore see patterns and rules in action, we can build theoretical models to make predictions and simulations (and games btw)

Since it's fair to say that mathematics is the science of patterns, it is plausible that physical descriptions often come in mathematical formulations, so that it can be understand as an efficient language of physics.

Neighboring disciplines like chemistry relay on physical theories to build on them,and then add shortcuts to fit their needs and interests, generating an own language for their field of study. But physicists may refer to them as anadd-on to physics.

Physics can basically explain all actions wich you can express in numbers.

But note that on a fundamental level physics describes 'how' things work, not necessarily 'why' they do it this way. The source of the basic and most fundamental physical constants and rules remains a mystery till this day.But of course there are theories on that as well, wich mostly can neither be proved or falsified.

The text is my own work and based of my general knowledge and quintessence of lectures on physics and other fields I attended.

(I would really appreciate the brainliest)

3 0

3 years ago

the electrostatic force between two objects is 40N. if the charge of one object is cut in half, and the distance is doubled, wha

n200080 [17]

Answer:

F1 = K Q1 Q2 / R1^2

F2 = K Q1 / 2 * Q2 / (2 R1)^2

F2 / F1 = 1/2 / 4 = 1/8

The new force is 5N (1/2 due to charge and 1/4 due to distance)

8 0

3 years ago

efrigerant-134a is expanded isentropically from 600 kPa and 70°C at the inlet of a steady-flow turbine to 100 kPa at the outlet.

PolarNik [594]

Answer:

Inlet : $v_i=0.0646\frac{m}{s}$

Outlet: $v_o=0.171\frac{m}{s}$

Explanation:

1) Notation and important concepts

Flow of mass represent "the mass of a substance which passes per unit of time".

Flow rate represent "a measure of the volume of liquid that moves in a certain amount of time"

Specific volume is "the ratio of the substance's volume to its mass. It is the reciprocal of density."

Isentropic process is a "thermodynamic process, in which the entropy of the fluid or gas remains constant".

We know that the flow of mass is given by the following expression

$\dot{m}=\frac{\dot{V}}{\upsilon}$ , where $\dot{V}$ represent the flow rate and $\upsilon$ the specific volume at the pressure and temperature given.

$A_i=0.5m^2$ is the inlet area

$P_i=600Kpa$ pressure at the inlet area

$T_i=70C$ temperature at the inlet area

$A_o=1m^2$ is the outlet area

$P_o=100Kpa$ pressure at the outlet area

$T_o=C$ temperature at the outlet area

$\dot{m}=0.75\frac{kg}{s}$ represent the flow of mass

If we look at the first figure attached Table A-13 we see that the specific volume for the inlet condition is

$\upsilon_i =0.04304\frac{kg}{m^3}$ and the entropy is $h_i=1.0645\frac{KJ}{KgK}=h_o$

With the value of entropy and the outlet pressure of 100 Kpa we can find we specific volume at the outlet condition since w ehave the entropy $h_o=1.0645\frac{KJ}{KgK}$

Since on the table we don't have the exact value we need to interpolate between these two values (see the second figure attached)

$h_1=1.0531\frac{KJ}{KgK} , \upsilon_1=0.22473\frac{kg}{m^3}$

$h_2=1.0829\frac{KJ}{KgK} , \upsilon_2=0.23349\frac{kg}{m^3}$

Our interest value would be given using interpolation like this:

$\upsilon=0.22473+\frac{(0.23349-0.22473)}{(1.0829-1.0531)}(1.0645-1.0531)=0.228\frac{kg}{m^3}$

2) Solution to the problem

Now since we have all the info required to solve the problem we can find the velocities on this way.

We know from the definition of flow of mass that $\dot{m}=\frac{\dot{V}}{\upsilon}$ , but since $\dot{V}=Av$ we have this:

$\dot{m}=\frac{Av}{\upsilon}$

If we solve from the velocity v we have this:

$v=\frac{\upsilon \dot{m}}{A}$ (*)

And now we just need to replace the values into equation (*)

For the inlet case:

$v_i=\frac{\upsilon_i \dot{m}}{A_i}=\frac{0.043069\frac{kg}{m^3}(0.75\frac{kg}{s})}{0.5m^2}=0.0646\frac{m}{s}$

For the oulet case:

$v_o=\frac{\upsilon_o \dot{m}}{A_o}=\frac{0.228\frac{kg}{m^3}(0.75\frac{kg}{s})}{1m^2}=0.171\frac{m}{s}$

7 0

3 years ago

Which of the following should you always use to protect yourself from hazardous moving parts of power tools and equipment

Andrew [12]

What are the following answers?

7 0

3 years ago