1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ira Lisetskai [31]
3 years ago
15

An object will only change its motion if a force is directly applied to it. is this a true statement?

Physics
1 answer:
skelet666 [1.2K]3 years ago
7 0
True
<span> An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.this is newtons first law</span>
You might be interested in
The emissivity of an ideal reflector has which of the following values?
Wittaler [7]

Emissivityis a measure of how much thermal radiation a body emits to its environment. On the other hand we have that reflectivity is a measure of how much is reflected, and transmissivity  is a measure of how much passes through the object. If a body is required to be ideally reflective to its maximum efficiency, the body should NOT have the property of transmissivity or emissivity. Therefore it should be 0 its emittivity.

Correct answer would be A : ZERO.

4 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
Can you ever absolutely prove that a hypothesis is correct? Explain.
Diano4ka-milaya [45]

Yes you can, with using scientific experiment.

Ask a question -- Do background Research -- Construct a Hypothesis --Test with an Experiment -- Procedure working? -- Yes or no? -- Analyze Data and Draw Conclusions

With an experiment you can discover if its correct or not.

Hope this helps ! <3

8 0
3 years ago
When a wire is made thicker its resistance what?
NeTakaya
Making a wire thicker has the same effect as making a road wider. It makes it easier for the electron traffic to flow. The resistance decreases, and the current (traffic) increases.
7 0
3 years ago
A motorcycle traveling at 25 m/s accelerates at a rate of 6 m/s2 for 4 seconds. What is the final speed of the motorcycle in m/s
givi [52]

Initial velocity = Vo= 25 m/s

Final velocity = V = x

Acceleration= a = 6 m/s^2

time= t = 4 seconds

Appy the equation:

V = Vo + at

Replacing:

V = 25 + 6(4) = 25 + 24 = 49 m/s

8 0
1 year ago
Other questions:
  • Which statement describes one feature of a closed circuit? Charges do not flow. Bulbs will not shine. The circuit is broken. The
    13·2 answers
  • An output is a Push or pull _________________________ on the object
    8·1 answer
  • Strong solar winds blew dust and gas out of the solar system during which phase of the development of the Sun?
    5·2 answers
  • Consult Multiple-Concept Example 15 to review the concepts on which this problem depends. Water flowing out of a horizontal pipe
    9·1 answer
  • If humans evolved from apes or chimps, why are the chimps and apes still here?
    11·2 answers
  • calculate the force between two objects that have masses of 20 kg and 100 kg separated by a distance of 2.6 m
    15·1 answer
  • A ball is thrown downward with an initial speed of 7m/s. the balls velocity after 3 seconds is m/s
    9·2 answers
  • The sun doesn't set during what season and at what latitude?
    5·1 answer
  • A 50 W light bulb is plugged into a standard
    9·1 answer
  • Which of the following correctly describes the law of conservation of matter?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!