Answer:
+70 km/h north
Explanation:
Answer:North/speeding up
Explanation:
does the sabre-tooth currirulum still exist at present?give examples of your evidence
Answer: Should the sabre tooth curriculum really exist at the moment? As far as I am concerned, the sabre tooth program should remain, because our school system needs to help people know how to do complex activities on their own and we let them do activities that will help them develop their brains as well as their skills.
Great schools promote better teaching because they have the most experience of teaching practice and are accountable for executing the instruction in the classroom. Teacher engagement is also vital for the effective and substantive implementation of the curriculum.
Sources: files.eric.ed.gov and James Kennedy Monash
A battery connected to two wires in parallel. Both wires are made of the same material and are of the same length, but the diameter of wire A is twice the diameter of wire B.
True or False for the following:
1) The resistance of wire B is four times as large as the resistance of wire A.
2) The power dissipated in wire A is 16 times the power dissipated in wire B.
3) The voltage drop across wire B is larger than the voltage drop across wire A.
4) The resistance of wire B is twice as large as the resistance of wire A.
5) The current through the battery is five times larger than the current through wire B.
Answer:
true 1
2 is false 2. 3 . 4. 5
Explanation:
For this exercise, let's calculate the different parameters and analyze the corresponding statements.
the resistance of each wire
R = ρ [tex]\frac{L}{A}[/tex]
wire B.
has a diameter of d₀
therefore its radius is r₀ = d₀ / 2
the area is A = pi r₀²
A = π d₀²/ 4
we subtitle
Ro = ρ [tex]\frac{L \ 4}{\pi d_o^2}[/tex]
R_b = R₀
wire A
the diameter is d = 2d₀
therefore the radius is r = d/2
r = d₀
resistance is
R_a = ρ [tex]\frac{L}{\pi d_o}[/tex]
R_a = 4 R₀
when examining the answers
1 is true
4 is false
Now let's calculate the power
P = V I
V = I R
P = V² / R
as they indicate that the cables are connected in parallel, the voltage in them is the same, therefore the potency depends on the resistance
wire B
P = V² / R_b
P_b = V² / R₀
wire A
P_a = v² / R_a
P_a = V² / 4R₀
P_a = ¼ P_b
2 is false
in a parallel circuit the waves are the same therefore
3 False
ohm's law is
V = I r
I = V / R
wire B
I_b = V / R_b
I_b = V / Ro
wire
I_a = V / R_a
I_a = V / 4 Ro
I_a = ¼ I_a
5 is false
liquids have higher coefficents of expansion than solids do in general. ture or false worth 29 points!
Answer:
true
Explanation:
Which choices describe advantages of wind energy over fossil fuels?
Select all that apply.
doesn't emit pollutants
renewable
freely available
O releases carbon dioxide instead of carbon monoxide
The advantages of wind energy over fossil fuels are that it does not emit pollutants, it is a renewable source of energy and it is a freely available source of energy.
What is wind energy?
The process that describes the generation of wind power or the mechanical power using the flow of wind itself, is known as wind energy.
Following are the advantages of wind energy over fossil fuels -
Free source of fuel.One of the cleanest forms of energy.Advance technologies are used for its extraction.Does not disrupt any sort of farmland operations.It is a clean fuel source and does not emit pollutants.It is a renewable source of energy.Thus, we can conclude that the advantages of wind energy over fossil fuels are that it does not emit pollutants, it is a renewable source of energy and it is a freely available source of energy.
Learn more about wind energy here:
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Consider a length of pipe bent into a U-shape. The inside diameter of the pipe is 0.5 m. Air enters one leg of the pipe at a mean velocity of 100 m/s and exits the other leg at the same magnitude of velocity, but moving in the opposite direction. The pressure of the flow at the inlet and exit is the ambient pressure of the surroundings. Calculate the magnitude and direction of the force exerted on the pipe by the airflow. The air density is 1.23 kg/m3 .
Answer:
The magnitude of the force exerted on the pipe by the air is 4830 N and it acts horizontally
Explanation:
Given the data in the question;
from the Newton's second law of motion;
F = ma
where m is the mass, a is acceleration and F is the force exerted on the pipe due to the airflow in it
now in terns of mass flow;
F = [tex]m^{"}[/tex]V
where [tex]m^{"}[/tex] is the mass flow rate, V is the velocity(
so
[tex]m^{"}[/tex] = pAV
[tex]m^{"}[/tex] = p × ([tex]\frac{\pi }{4}[/tex] d² ) × V
where d is the diameter of the pipe( 0.5 m)
p is the density( 1.23 kg/m³ )
velocity v is 100 m/s
so we substitute
[tex]m^{"}[/tex] = 1.23 × ([tex]\frac{\pi }{4}[/tex] (0.5)² ) × 100
[tex]m^{"}[/tex] = 30.75 × [tex]\frac{\pi }{4}[/tex]
[tex]m^{"}[/tex] = 24.15 kg/s
Now lets write the equation for the force exerted on the pipe by the airflow
F = [tex]m^{"}[/tex]( V₁ - V₂)
where V₁ is velocity at inlet ( 100 m/s )
V₂ is velocity at exit ( - 100 m/s )
so we substitute
F = 24.15 ( 100 - (-100))
F = 24.15 × 200
F = 4830 N
The pipe is symmetric about horizontal axis so the force should also b acting only in the horizontal direction since any force component in the vertical direction is nullified due to this symmetry
Therefore, The magnitude of the force exerted on the pipe by the air is 4830 N and it acts horizontally
How do intermolecular forces (IF) and internal kinetic energy (KE) compare in gases?
IF = 0, KE is large
IF < KE
IF ≥ KE
IF > KE
Please help me!
Answer:
IF < KE
Explanation:
The kinetic energy of the gas is greater than the intermolecular forces making the molecules have room to move around without disruption. In a lot of gases, there are sometimes no intermolecular forces between all the particles.
Best of Luck!
a. Describe the big bang theory. (1 point) b. Match each model of the universe with the future it predicts. (1 point) A. Closed B. Flat C. Open _____ The universe will stop expanding but will not collapse. _____ The universe will continue to expand forever. _____ The universe will stop expanding and then collapse back to its point of origin. c. Match each observation to the conclusion it supports in the big bang theory. (1 point) A. Light from other galaxies is shifted toward the red end of the spectrum. B. Cosmic background radiation appears uniform across the sky. C. The amount of helium in the universe matches predictions. _____ Nucleosynthesis of light elements occurred shortly after the expansion of the original ball of energy. _____ The universe is expanding. _____ The universe began from a single point.
Answer:
A)
The Big Bang is the earliest known event in the observable Universe, its earliest known phase of evolution, and the name of the model for this process. According to this scenario, the Big Bang took place around 13.800 million years ago, when the known Universe emerged from very dense and hot matter. This theory is based on observations showing that space is expanding from an initial state where all the matter in the universe had a very high density and temperature, to a more cold and stable one.
B)
A. Closed. The universe will stop expanding and then collapse back to its point of origin.
B. Flat. The universe will stop expanding but will not collapse.
C. Open. The universe will continue to expand forever.
10/12
11.
You drive the 10 miles to the mall at an average speed of 40 mph. On
the way home, you hit severe traffic and had to drive at an average
speed of 10 mph. What is your average speed for the trip?
A polycondensation reaction takes place between 1.2 moles of a dicarboxylic acid, 0.4 moles of glycerol (a triol) and 0.6 moles of ethylene glycol (a diol). A.Calculate the critical extents of reaction for gelation using (i) the statistical theory of Flory and (ii) the Carothers theory.B.Comment on the observation that the measured value of the critical extent of reaction is 0.866.
Answer:
A) i) using statistical theory of floxy
(Pa)c = 0.816
(Pb)c = 0.816
ii) using Carothers theory
( Pc ) = 0.917
B) To Obtain the measured value of critical extent of reaction ( 0.866) 1 mol of Glycerol will react with 1 mol of dicarboxylic acid, but the same can not be applied to our obtained value because our stoichiometry is different
Explanation:
Given data :
Polycondensation reaction takes place between : 1.2 moles of dicarboxylic acid , 0.4 moles of glycerol and 0.6 moles of ethylene glycol
A) Calculate the critical extents of reaction for gelation
i) using statistical theory of floxy
(Pa)c = 0.816
(Pb)c = 0.816
ii) using Carothers theory
( Pc ) = 0.917
attached below is the detailed solution
B) To Obtain the measured value of critical extent of reaction ( 0.866) 1 mol of Glycerol will react with 1 mol of dicarboxylic acid, but the same can not be applied to our obtained value because our stoichiometry is different
A 80 Kg monkey climbs a 15 meter tree in half a minute. What is the magnitude of power the monkey demonstrated?
a. 13.1 J/S
b. 392 J/S
c. 784 J/s
d. 11760 J/s
Answer:
Power = Work / Time
P = m g h / t = 80 kg * 9.8 m/s^2 * 15 m / 39 s = 320 N m/ s = 392 J / s
= 392 Watts
The magnitude of power the monkey demonstrated is equal to 392 J/S.
Power calculation
To measure the power of a given body, one must relate its weight, the displacement performed and the time in which the movement was performed, in such a way:
[tex]P = \frac{m\times g\times d}{t}[/tex]
Thus, applying the values given by the statement we have:
[tex]P = \frac{80 \times 9.8 \times 15}{30}[/tex]
[tex]P = 392 J/s[/tex]
So, the power performed by the monkey climbing 15 meters is equal to 392J/s.
Learn more about power in: brainly.com/question/8671146
Which choice describes a concern with wind energy?
O may harm bird and bat populations
o negative impact on river ecosystems
O turbines are cheaply made
O could interfere with pollen distribution
A concern which is related to the wind energy is that these could interfere with the pollen distribution. Thus, the correct option is D.
What is Wind energy?Wind power or wind energy is mostly used in the wind turbines to generate electricity. The wind power is a popular, sustainable, renewable energy source which has a much smaller impact on the surrounding environment than that of burning fossil fuels.
Some disadvantages of wind energy include noise and visual pollution, wind power is not a remote power, and the effects or impact on the environment including interference with the pollen distribution.
Therefore, the correct option is D.
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How is the chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe)?
A.
In an iron crystal, the atoms are joined by sharing electrons. In carbon dioxide, atoms of carbon and oxygen are held together by freely moving electrons.
B.
In a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons.
C.
In an iron crystal, the atoms are joined by their opposite electrical charges. In carbon dioxide, atoms of carbon and oxygen are held together by freely moving electrons.
D.
In a carbon dioxide molecule, atoms of carbon and oxygen are joined by their opposite electrical charges. In an iron crystal, the atoms are held together by freely moving electrons.
Answer:
I'ts B
Explanation:
:p
The chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe) in a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons. Therefore, option B is correct.
What is chemical bonding ?The term chemical bonding is defined as the formation of a chemical bond between two or more atoms, molecules, or ions to form a chemical compound.
There are three main types of chemical bonding that are ionic bonding, covalent bonding, and metallic bonding.
The chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe) because in a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons.
Thus, option B is correct.
To learn more about the chemical bonding, follow the link;
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(a) What is the electric field 4.00 m from the center of the terminal of a Van de Graaff with a 3.00 mC charge, noting that the field is equivalent to that of a point charge at the center of the terminal?
______ N/C
(b) At this distance, what force does the field exert on a 2.00C charge on the Van de Graaff's belt?
_____ N
Answer:
a) E = 1.69 10⁶6 N / C, b) F = 3.38 10⁶ N
Explanation:
a) In this exercise using Gauss's law we can consider the charge of the generator sphere as if it were at its center, therefore the electric field is
E = k [tex]\frac{q}{r^2}[/tex]
let's calculate
E = 9 10⁹ 3.00 10⁻³ / 4²2
E = 1.6875 10⁶ N / C
E = 1.69 10⁶6 N / C
b) let's calculate the electric force
F = q E
F = 2.00 1.69 10⁶
F = 3.38 10⁶ N
Help me please I wrote some but I am still stuck
Answer:
write something like after the spacecraft launched all of the potential energy transformed into kinetic energy causing the spacecraft to go at an abnormal spped.
Explanation:
Which is the best description of biodiversity?
1. All animals in an ecosystem
2. The variety of the type of life within the biosphere
3. The study of life
3. The variety of plants on Earth
Answer:2
Explanation:
An uncharged capacitor and a resistor are connected in series with a switch and a 12 V battery. At the instant the switch is closed, the voltage across the resistor is
Answer:
V = 12 V
Explanation:
Since a capacitor can't change the voltage between its plates instantaneously, this means that just after the switch is closed, the voltage through the capacitor is zero.So, the current that flows in this moment is the same that would flow in a series circuit with only one resistor connected to the battery.Applying KVL to the circuit (neglecting the presence of the capacitor which can be replaced by a short circuit just after closing the switch), the voltage through the resistor must be equal to the one of the battery, i.e., 12 V.why all traveller prefer to travel easily in the morning and night and not when the sun is hot
Answer:
Travelers prefer to travel in morning because arthat time the temperature ️ is not too hot and they can easily travel here and there without any problem. and they also prefer to travel in night because moderate temperature ....
Friction occurs when microscopic hills and valleys stick together
true or false
Answer:
true
Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Explanation:
true but not going to copy and paste,
g A particle is trapped in a 20 nm wide infinite potential well. What is the wavelength of the particle corresponding to n
Question:
A particle is trapped in a 20 nm wide infinite potential well. What is the wavelength of the particle corresponding to n = 7 in nm?
Answer:
[tex]\lambda_n = 5.71\ nm[/tex]
Explanation:
Given
[tex]L = 20nm[/tex] --- the width
[tex]n = 7[/tex]
Required
Determine the wavelength ([tex]\lambda[/tex])
This is calculated as:
[tex]\lambda_n = \frac{2L}{n}[/tex]
Substitute values for L and n
[tex]\lambda_n = \frac{2*20nm}{7}[/tex]
[tex]\lambda_n = \frac{40nm}{7}[/tex]
[tex]\lambda_n = \frac{40}{7}nm[/tex]
[tex]\lambda_n = 5.71428571\ nm[/tex]
[tex]\lambda_n = 5.71\ nm[/tex] --- approximated to 3 significant figures
What causes an electromagnet to create a magnetic field?
A.The Earth's magnetic field.
B.The poles are attracted to each other.
C.The iron is wrapped with a coiled wire.
D.There is a current flowing through the wire.
Answer:
D
Explanation:
Have a great day ;)
PLZ HELP IT URGENT
Describe what Rutherford would have seen in his gold foil experiment if J.J. Thompson's Plum Pudding model was completly accurate.
Answer: i use this in ss class
Explanation:
A 0.15kg baseball is pushed with a 100N force. What will its acceleration be?
How long will it take a 200kg stationary man in space to travel 20m if he throws a 10 kg object at a velocity of 30m/s?
A monk is sitting atop a mountain in complete rest in meditation. What is the Kinetic
Energy of the monk? (assume mass of 65 kg and the mountain's height was 1000 m)
4,225,000
No Kinetic Energy - because there is no movement
637,000
65.000
Answer:
No kinetic energy-because there is no movement
Explanation:
It states that the monk is at complete rest so there is no movement.
A high frequency sound will have a ?
Answer:
The frequency of a sound wave is what your ear understands as pitch. A higher frequency sound has a higher pitch and the lower the period
Answer:
High-frequency sound waves produce high-pitched sounds, and low-frequency sound waves produce low-pitched sounds.
Select the correct answer.
A car is moving at a constant speed along a straight line. Which statement is true about the forces acting on the car?
ОА.
The net force acting on the car from all directions is zero.
o
B.
The net force acting on the car is greater than the car's weight.
O c.
The net force acting on the car is in the direction of the car's motion.
OD.
The net force acting on the car is in the opposite direction of the car's motion.
Answer:
ОА.
The net force acting on the car from all directions is zero.
Explanation:
Constant speed along a straight line
It means constant magnitude of velocity without chainging direction
It means constant velocity. Which means acclecration is zero
By Newton's second law:
[tex]F=ma[/tex]
Net force is also zero
A 5 kg block rests on a rough horizontal table. A rope is
attached to the block and is pulled with a force of 11N to the
left. As a result, the block accelerates at 2 m/s2. The coefficient
of kinetic friction between the block and the table is (round
to the nearest hundredth)
Answer:
Approximately [tex]0.02[/tex] (assuming that [tex]g = 9.81\; \rm N \cdot kg^{-1}[/tex], and that the block was initially moving to the left.)
Explanation:
Apply Newton's Second Law to find the net force on this block.
Mass of this block: [tex]m = 5\; \rm kg[/tex].
Acceleration of this block: [tex]a = 2\; \rm m \cdot s^{-2}[/tex].
[tex]\begin{aligned}\text{Net force} &= m \cdot a \\ &= 5\; \rm kg \times 2\; \rm m \cdot s^{-1} = 10\; \rm N\end{aligned}[/tex].
The block is moving and accelerating towards the left. Hence, friction (which opposes motion) would be towards the right and would be opposite to the direction of the [tex]11\; \rm N[/tex] pulling force.
Therefore, the expression for the net force on this object would be:
[tex](\text{Net force} ) = (\text{Pulling force}) - (\text{Friction})[/tex].
[tex]10\; \rm N = 11\; \rm N - (\text{Friction})[/tex].
Hence:
[tex]\text{Friction} = 11\; \rm N - 10\; \rm N = 1\; \rm N[/tex].
The question states that this table is horizontal. Weight of the block (downwards) and normal force from the table (upwards) are the only two forces on this block in the vertical direction. Hence, the magnitude of the normal force on this block would equal to that of the weight of the block:
[tex]\begin{aligned} |\text{Normal force}| &= |\text{Weight}| \\ &= m \cdot g \\ &= 5 \; \rm kg \times 9.81\; \rm N \cdot kg^{-1} = 49.05\; \rm N\end{aligned}[/tex].
Calculate the constant of kinetic friction between this block and the table:
[tex]\begin{aligned}\mu_{\text{k}} &= \frac{\text{Friction}}{\text{Normal force}} \\ &= \frac{1\; \rm N}{49.05\; \rm N} \approx 0.02\end{aligned}[/tex].
Which one of the following is an example of an acid-base reaction?
Answer:
B
Explanation:
Acid reacts with base to give salt and water.
HCL - Acid
Mg(OH)2 - Base
H2O - Water
MgCl2 - Salt
Answer: B because A p e x
Explanation:
The manufacturer of a 9V dry-cell flashlight battery says that the battery will deliver 20 mA for 80 continuous hours. During that time the voltage will drop from 9 V to 6 V. Assume the drop in voltage is linear with time. How much energy does the battery deliver in this 80 h interval
Answer:
17280 J or 17.28 kJ
Explanation:
Given that the voltage drop,
U = U2 - U1
U = 9 - 6
U = 3V
Also, we're told that the current, I is equal to 20 mA with the discharge time, t being 80 hrs.
Converting the time from h oi urs to seconds, we have
t = 80 * 3600
t = 288000
Now, to find the energy needed, we're going to use the formula
w = pt, where p = U * I
p = 3 * 20*10^-3
p = 60*10^-3
w = 60*10^-3 * 288000
w = 17280 J or 17.28 kJ
Therefore, the total energy the battery delivers in the 80 hrs is 17.28 kJ
How long must a 0.54-mm-diameter aluminum wire be to have a 0.42 A current when connected to the terminals of a 1.5 V flashlight battery
Answer:
L = 30.85 m
Explanation:
First, we calculate the resistance of the wire by using Ohm's Law:
V = IR
where,
V = Potential Difference = 1.5 V
I = Current = 0.42 A
R = Resistance of Wire = ?
Therefore,
[tex]R = \frac{1.5\ V}{0.42\ A}\\\\R = 3.57\ Ohms[/tex]
Now, the cross-sectional area of wire will be:
[tex]Area = A = \frac{\pi d^{2}}{4}\\\\A = \frac{\pi (0.00054\ m)^{2}}{4}\\\\A = 2.29\ x\ 10^{-7}\ m^{2}[/tex]
Now, the resistance of the wire is given as:
[tex]R = \frac{\rho L}{A}\\\\L = \frac{RA}{\rho}[/tex]
where,
L = Length of Wire = ?
ρ = resistivity of aluminum = 2.65×10⁻⁸ Ohm.m
Therefore,
[tex]L = \frac{(3.57\ Ohms)(2.29\ x\ 10^{-7}\ m^{2})}{2.65\ x\ 10^{-8}\ Ohm.m}[/tex]
L = 30.85 m