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
storchak [24]
3 years ago
13

A dad takes his kids to their school just 8.0 miles down the road but with traffic it takes him 30 minutes and the fastest he ca

n go is 35 mi/hr. One of his children has forgotten his lunch, so the dad goes back, gets the lunch, and returns to the school. It takes him just an additional 30 minutes since traffic has cleared. What is his average velocity for the morning?
A 8 mi/hr
B 16 mi/hr
C 24 mi/hr
D 35 mi/hr
Physics
1 answer:
VARVARA [1.3K]3 years ago
8 0

Answer:C 24 mi/hr

Explanation:

You might be interested in
Can you please answer these ASAP!
SVEN [57.7K]

Answer:

Let's explain this briefly.

Suppose that we have a piece of ice (this is, solid water) now we give energy to the piece of ice, so the temperature of the ice increases. There is a point where the piece of ice will start a change of phase, at this point the temperature of the ice stops increasing because all the energy we give to the ice is used in the change of phase.

Once we have a complete change of phase, the temperature can increase again, and now we will have liquid water.

If we keep increasing the temperature we will see this happen again, when we have the transition from liquid to gas.

(and a similar thing happen when we have a material in a given phase and we remove heat from the material).

In the images we can see the different changes of phase of water.

1) In the first image we can see the circle in a part where the temperature is constant, so the temperature does not change in this part, which means that there is a change of phase happening.

2) Here we have the circle in a diagonal line, so here the temperature is changing, meaning that we have an increase of temperature in this region.

3) Here we want to know what the x-axis represents, this should rerpesent the energy that is being given to the material (so in some parts we see that the temperature increases and in other parts we see that the material changes of phase)

Then here the correct option is heat over time.

4) The freezing point is the temperature in which the change of phase from liquid to solid happens (or solid to liquid).

In the graph we can see that this change of phase happens at the temperature T = -210°C

Then the correct option is -210°C (The last option)

4 0
3 years ago
A figure skater begins spinning counterclockwise at an angular speed of 3.2 π rad/s. During a 4.5 s interval, she slowly pulls h
avanturin [10]

Answer:

Explanation:

.93 rad per secundo

7 0
3 years ago
The electromagnetic wave that delivers a cellular phone callto
spin [16.1K]

Answer:

E=2.41\cdot 10^{-5} J

Explanation:

The intensity of an electromagnetic wave can be expressed in terms of the magnetic field using the next relationship:

I_{average}=\frac{cB_{0}^{2}}{2\mu_{0}} (1)

  • c is the speed of light (3*10⁸ m/s)
  • μ₀ is the permeability of free space (in vacuum ) (1.26*10⁻⁶ N/A²)
  • B₀ is the magnetic field

I_{average}=\frac{3\cdot 10^{8}(1.5\cdot 10^{-10})^{2}}{2\cdot 1.26\cdot 10^{-6}}

I_{average}=2.68\cdot 10^{-6} W/m^{2}

Now, let's define the relationship between power (P) and average intensity (I).

I_{average}=\frac{P}{A}

  • P is the power
  • A is the area crossed

So we can calculate the power.

P=I_{average}\cdot A=2.68\cdot 10^{-6}\cdot 0.20=5.37\cdot 10^{-7} W

Finally, energy is the product of P times time, so:

E=P\cdot t=5.37\cdot 10^{-7} \cdot 45=2.41\cdot 10^{-5} J

I hope it helps you!

5 0
3 years ago
NEED HELP ASAP
bogdanovich [222]
The equation for gravity is given by:

F_G =  \frac{G m_1 m_2}{r^2}

1. If r goes up by a factor of 3, gravity goes down by a factor of 9.
2. If m₁*m₂ goes up by a factor of 24, gravity goes up by a factor of 24.
5 0
3 years ago
Use the diagram to answer the questions below.
svet-max [94.6K]

Answer:

1. because of the tilted axis of earth the seasons in northern hemisphere are the exact opposite of the southern. because the sunrays reaches the earth an different points and when the earth moves around the sun it changes the hemisphere which is tilted to the sun.

2. the northern hemisphere is in Winter and the southern in summer. because the southern is tilted to the sun and the northern not so less sunrays reaches the northern hemisphere.

I'm sorry my explanation are bad

4 0
3 years ago
Other questions:
  • A 10 m long clothesline is strung so that it is perfectly horizontal. when a shirt is hung in the exact center the line sags to
    15·1 answer
  • Boyle's Law states that when a sample of gas is compressed at a constant temperature, the pressure P and volume V satisfy the eq
    9·1 answer
  • What type of relationship exists between the length of a wire and the resistance, If all other factors remain the same?
    6·2 answers
  • Why would scientists call solids and liquids a condensed phase of matter?
    8·1 answer
  • If you know the distance of an earthquake epicenter from three seismic stations, how can you find the exact location of the epic
    12·1 answer
  • Anyone knows this please help me
    6·1 answer
  • Does mass affect the final velocity of an object if the object begins with a high initial velocity?
    5·1 answer
  • According the Merriam Webster dictionary the definition of falling is, "to descend freely by the force of gravity".
    13·1 answer
  • Có thể một lực hướng tâm tạo ra công trên một vật hay không? Hãy giải thích
    14·1 answer
  • A bullet of mass 0.045 kg is travelling horizontally at 400 m/s when it strikes a stationary wooden block of mass 16 kg. The bul
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!