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3 years ago

What is the Scientific definition of friction?

2 answers:

8 0

Friction<span> is the resistance to motion of one object moving relative to another. It is not a fundamental force, like gravity or electromagnetism. Instead, scientists believe it is the result of the electromagnetic attraction between charged particles in two touching surfaces.
Hope this is of great help to you, and happy studying~!
~Mistermistyeyed.</span>

Jlenok [28]3 years ago

4 0

Friction is the resistance when an object moves together with a surface. Hope that helps.

You might be interested in

Neurons that relay information within the cns and are the location of information processing are called __________.

emmainna [20.7K]

Answer:

Interneurons

Explanation:

An interneuron or integrative neuron is a central nervous system neuron, usually small and short axon, that interconnects with other neurons; but never with sensory receptors or muscle fibers, allowing more complex functions.

The interneuron, also called the association neuron, has the function of analyzing sensory information and storing part of it. It also acts on reflex acts, transforming a stimulus in response at the level of the spinal cord. They are located between sensory and motor neurons and are located in the upper nerve centers. Interneurons are multipolar neurons, which connect afferent neurons with efferent neurons in the neuronal or nerve tracts. In other words, they function as a communicational bridge, intercommunicating sensory neurons with motor neurons. Like motor cells, interneurons are only found in the central nervous system. In contrast to the peripheral nervous system, all CNS neurons appear to be interneurons, as they are in communication with many other neurons. However, the term "interneuron" refers to neurons that have axon and dendritic extensions of local extension and not distant, that is, short.

7 0

3 years ago

Which sentence provides evidence that heat travels from Earth’s mantle up to its crust?

olasank [31]

B. Earth’s outer surface is cooler than its interior layers.

Explanation:

The option given above is showing us that the temperature in the interior of the earth is higher than the temperature in the outer layer.
There is travel of heat from the inner core of the earth to the earth's crust. Due to the loss of heat when it reaches the outer layer, there arises a temperature difference.
The heat loss is due to the absorption of heat during its transfer. Hence, option B is the answer.

7 0

3 years ago

The circuit you should use to find the open-circuit voltage is

fiasKO [112]

Answer:

Incomplete questions check attachment for circuit diagram.

Explanation:

We are going to use superposition

So, we will first open circuit the current source and find the voltage Voc.

So, check attachment for open circuit diagram.

From the diagram

We notice that R3 is in series with R4, so its equivalent is given below

Req(3-4) = R3 + R4

R(34) = 20+40 = 60 kΩ

Notice that R2 is parallel to the equivalent of R3 and R4, then, the equivalent of all this three resistor is

Req(2-3-4) = R2•R(34)/(R2+R(34))

R(234) = (100×60)/(100+60)

R(234) = 37.5 kΩ

We notice that R1 and R(234) are in series, then, we can apply voltage divider rule to find voltage in R(234)

Therefore

V(234) = R(234) / [R1 + R(234)] × V

V(234) = 37.5/(25+37.5) × 100

V(234) = 37.5/62.5 × 100

V(234) = 60V.

Note, this is the voltage in resistor R2, R3 and R4.

Note that, R2 is parallel to R3 and R4. Parallel resistor have the same voltage, then voltage across R2 equals voltage across R34

V(34) = 60V.

Now, we also know that R3 and R4 are in series,

So we can know the voltage across R4 which is the Voc we are looking for.

Using voltage divider

V4 = Voc = R4/(R4 + R(34)) × V(34)

Voc = 40/(40+60) × 60

Voc = 24V

This is the open circuit Voltage

Now, finding the short circuit voltage when we short circuit the voltage source

Check attachment for circuit diagram.

From the circuit we notice that R1 and R2 are in parallel, so it's equivalent becomes

Req(1-2) = R1•R2/(R1+R2)

R(12) = 25×100/(25+100)

R(12) = 20 kΩ

We also notice that the equivalent of Resistor R1 and R2 is in series to R3. Then, the equivalent resistance of the three resistor is

Req(1-2-3) = R(12) + R(3)

R(123) = 20 + 20

R(123) = 40 kΩ

We notice that, the equivalent resistance of the resistor R1, R2, and R3 is in series to resistor R4.

So using current divider rule to find the current in resistor R4.

I(4) = R(123) / [R4+R(123)] × I

I(4) = 40/(40+40) × 8

I(4) = 4mA

Then, using ohms law, we can find the voltage across the resistor 4 and the voltage is the required Voc

V = IR

V4 = Voc = I4 × R4

Voc = 4×10^-3 × 40×10^3

Voc = 160V

Then, the sum of the short circuit voltage and the open circuit voltage will give the required Voc

Voc = Voc(open circuit) + Voc(short circuit)

Voc = 24 + 160

Voc = 184V.

3 0

3 years ago

Chose the word that correctly completes the following sentence: Kirchoff's junction law expresses the conservation of ____. a) m

Radda [10]

Answer:A- mass charge.

This can also be called current.

Explanation:

This is Kirchhoff’s 2nd law.

Kirchhoff’s junction law states that the sum of current(mass charge) flowing in and out of the junction must be equal to zero. This law emphasizes conservation of charge and energy. Charge is also a form of energy and it can neither be created nor destroyed.

5 0

2 years ago

A beam of protons is moving toward a target in a particle accelerator. This beam constitutes a current whose value is. (a) How m

Gelneren [198K]

Answer:

a. 5 × 10¹⁹ protons b. 2.05 × 10⁷ °C

Explanation:

Here is the complete question

A beam of protons is moving toward a target in a particle accelerator. This beam constitutes a current whose value is 0.42 A. (a) How many protons strike the target in 19 seconds? (b) Each proton has a kinetic energy of 6.0 x 10-12 J. Suppose the target is a 17-gram block of metal whose specific heat capacity is 860 J/(kg Co), and all the kinetic energy of the protons goes into heating it up. What is the change in temperature of the block at the end of 19 s?

Solution

i = Q/t = ne/t

n = it/e where i = current = 0.42 A, n = number of protons, e = proton charge = 1.602 × 10⁻¹⁹ C and t = time = 19 s

So n = 0.42 A × 19 s/1.602 × 10⁻¹⁹ C

= 4.98 × 10¹⁹ protons

≅ 5 × 10¹⁹ protons

The total kinetic energy of the protons = heat change of target

total kinetic energy of the protons = n × kinetic energy per proton

= 5 × 10¹⁹ protons × 6.0 × 10⁻¹² J per proton

= 30 × 10⁷ J

heat change of target = Q = mcΔT ⇒ ΔT = Q/mc where m = mass of block = 17 g = 0.017 kg and c = specific heat capacity = 860 J/(kg °C)

ΔT = Q/mc = 30 × 10⁷ J/0.017 kg × 860 J/(kg °C)

= 30 × 10⁷/14.62

= 2.05 × 10⁷ °C

5 0

2 years ago