Answer:
4Al + 3O2 + heat ------> 2Al2O3
Explanation:
It is endothermic reaction.
Researchers have found that the larvae of all North American firefly species glow as a warning sign to ward off predators. However, the presence and use of lighting organs in adult fireflies vary greatly. Some species use glowing or light flashes as mating signals, while other species produce pheromones as mating signals and do not glow at all. Discuss how the physical characteristics and mating behavior of North American fireflies support the theory of speciation. In your discussion, provide a hypothesis to explain the driving force behind the differences in mating signals among the species.
Explanation:
The theory of speciation confirms what happens with fireflies, only fireflies that are part of the same species can reproduce among themselves, which means that fireflies that use pheromones as mating signals will attract fireflies that use that same form or mechanism of reproduction.
Some mechanisms that allow this type of differentiation or speciation to occur are: seasonal or geographic isolation and sexual isolation due to behavior or conduct.
Speciation allows the formation of new populations of organisms that share the same physiological and genetic characteristics. Therefore, the adult fireflies that shine as a mating signal are possibly found in the same geographical position and their physiological and genetic characteristics are compatible with those of his own species.
What is the electrical power when the current is 20 amps and the voltage is 15 volts? *
A. 1.33 watts
B. 300 watts
C. 35 watts
Objects in space appear to change position as they orbit the sun. What is this phenomenon called? *
A. Nebular theory
B. Stellar theory
C. Parallax
The moon lacks an atmosphere because its gravity is too STRONG and forces gas molecules into outer space. *
A. True
B. False
Heat pumps move heat from __________ to __________ areas & REQUIRES energy.
A. cold, hot
B. hot, cold
Answer:
The power is 300 watts.
Explanation:
Given that,
Current, I = 20 a
Voltage, V = 15 volts
The electrical power of any device is given by the product of current and voltage. It can be given by :
P = VI
So,
P = 15 × 20
= 300 W
So, the power is 300 watts.
Danny measures the temperature of a 1.0-kg sample of sand and a 1.0-kg sample of soil. He then leaves both samples in the Sun for the 2.0 hours. At the end of this time, he measures their temperatures again.
A.
The soil absorbed more heat than the sand.
B.
The sand absorbed more cold energy than the soil.
C.
The soil absorbed more cold energy than the sand.
D.
The sand absorbed more heat than the soil.
Answer:
The sand absorbed more heat than the soil.
Explanation:
your welcome
1 7 points If you take less time to perform a task, you have less power output. O True O False
True
The rate at which work is done is referred to as power. A task done quite quickly is described as having a relatively large power. The same task that is done more slowly is described as being of less power. Both tasks require he same amount of work but they have a different power.
Why does it take more force to move a heavy box up a ramp than to move the same box down the ramp?
A.There is more friction on the bottom of the box when going up a ramp.
B.Gravity is pushing the box up the ramp at the same time you are pushing the box up the ramp.
C.When you push an object up a ramp, you are working against atmospheric pressure, which is pushing down.
D.When you push an object up a ramp, you are working against gravity, which pulls the box downward.
A wave is moving at the rate of 40 cm/s. Its wavelength is 5 cm. What is the frequency of the wave? INCLUDE THE CORRECT UNIT!
Answer:
Solution given:
velocity=40cm/s
wave length=5cm
we have
frequency =velocity/wavelength=40/5=8hertz.
the frequency of the wave is 8 hertz.
Find the equivalent resistance of this
circuit.
Ri
R2
1002
2002
R3
600 12
Answer:
63016
Explanation:
Ri+R2+R3 this is called series circuit
Answer:
200
Explanation:
100+200=300
1/300+1/600=200
Se dea caer una pelota de basquetbol desde una altura de 90 metros.Calcular: El tiempo en que demorara en caer y a velcidad con la que llega al suelo
Answer:
1. t = 4.24 s
2. [tex]v_{f} = 42.43 m/s [/tex]
Explanation:
Podemos encontrar el tiempo de caída con la siguiente ecuación:
[tex] v_{f} = v_{0} + gt [/tex] (1)
En donde:
[tex] v_{f}[/tex]: es la velocidad final de la pelota
[tex] v_{0}[/tex]: es la velocidad inicial = 0 (se deja caer)
g: es la aceleración debida a la gravedad = 10 m/s²
Debemos hallar primero la velocidad final. Podemos usar la ecuación:
[tex] v_{f}^{2} = v_{0}^{2} + 2gh [/tex] (2)
En donde:
h: es la altura = 90 m
[tex] v_{f} = \sqrt{2gh} = \sqrt{2*10 m/s^{2}*90 m} = 42.43 m/s [/tex]
Entonces, la velocidad con la que la pelota llega al suelo es 42.43 m/s.
Ahora podemos encontar el tiempo que tarda en caer la pelota resolviendo la ecuación (1) para "t":
[tex] t = \frac{v_{f}}{g} = \frac{42.43 m/s}{10 m/s^{2}} = 4.24 s [/tex]
Por lo tanto, la pelota tarda 4.24 segundos en caer.
Espero que te sea de utilidad!
A sled drops 50 meters in height on a hill. The mass of the rider and sled is 70 kg and the sled is going 10 m/s at the bottom of the hill. What is the efficiency of energy conversion from potential to kinetic?
Answer:
Efficiency = 10.2 %
Explanation:
Given the following data;
Mass = 70 kg
Height = 50 m
Velocity = 10 m/s
We know that acceleration due to gravity is equal to 9.8 m/s².
To find the efficiency of energy conversion from potential to kinetic;
First of all, we would determine the potential energy;
P.E = mgh
P.E = 70 * 9.8 * 50
P.E = 34300 J
For the kinetic energy;
K.E = ½mv²
K.E = ½ * 70 * 10²
K.E = 35 * 100
K.E = 3500
Therefore, Input energy, I = 34300 J
Output energy, O = 3500 J
Next, we find the efficiency;
Efficiency = O/I * 100
Substituting into the formula, we have;
Efficiency = 3500/34300 * 100
Efficiency = 0.1020 * 100
Efficiency = 10.2 %
What is the law of conservation of energy?
a
Energy can be changed from one form to another
form but cannot be created nor destroyed.
b An object at rest tends to stay at rest.
C
The right answer is not given.
The change in energy is equal to the
d amount of heat added plus the amount of
work done
Answer:
The answer is A
Calculate the distance between a 3.0 x 10^-5 charge and a 2.0 x 10^-6 2 points
C charge if the force between them is 1000 N.
Answer:
thanks for answer:)
Explanation:
7. What is the force on a 1000 kg elevator that is falling freely under the acceleration of gravity
only (10m/s?)?
Basketball was developed so that athletes would have a sport to play during the _________.
A. Fall
B. Winter
C. Spring
D. Summer
Answer:
B. Winter
Explanation:
The table below shows the speed of sound waves from musical sound sources at 20°C. Which conclusion can be made based on the information in the table? Wave speed and wavelengths can vary inversely to produce the same frequency. Frequency and wave speed can vary directly to produce the same wavelength. Wavelengths and frequency can vary inversely to produce the same wave speed. Frequency and wavelengths can vary directly to produce the same wave speed. Mark this and return
Answer:
c
Explanation:
Answer:
C
Explanation:
Took it on edg
A 12-ohm resistor is connected in series with a 23-ohm resistor. They are placed across a 120-volt power source. What is the current in the circuit?
A) 35 amps
B) 10 amps
C) 5.2 amps
D) 3.4 amps
Answer:
3.43 A
Explanation:
Applying,
V = IR'.............. Equation 1
Where V = Voltage, I = current, R' = Total resistance
Make I the subject of the equation
I = V/R'........... Equation 2
From the question
Given: V = 120 volt, R' = (12+23) = 35 0hm
Substitute these values into equation 2
I = 120/35
I = 3.43 A
How does a parallel circuit change when a branch is added?
The total resistance increases, so the current in the circuit decreases.
The total resistance decreases, so the current in the circuit increases.
The total resistance increases, so bulbs shine at a lower brightness.
The total resistance decreases, so bulbs shine at a higher brightne
2.4.6.8.
10th term (it's from qbasic)
Answer:
18
Explanation:
2,4,6,8..Are in A.PCommon Difference=d=4-2=3First term=a=2We know that
[tex]\boxed{\sf a_n=a+(n-1)d}[/tex]
━☞a10=2+(10-1)×2
━☞2+9×2
━☞2+18
━☞18
How come we can see orange? In simple words.
Answer:
When sunlight shines through an orange solution, the violet, blue and green wavelengths are absorbed. The other colors pass through.
Which of the following could be included in your gamer's creed that would help keep gamers safe?
A. I will work hard and play harder. Games are my life.
B. I will use privacy features that gaming sites provide to ensure I do not share personal information with strangers.
C. I will do whatever I can to win games I play online.
D. I will share the game equally with my friends and family.
swered
Answer:
The answer is B. I will use privacy features that gaming sites provide to ensure I do not share personal information with strangers.
Explanation:
It keeps you safe online
Answer: the answer is b
Explanation:
Which of the following are true about electrons? a.) They are positively charged b.) They are negatively charged c.) They are found inside the nucleus d.) a & c
Answer:
A and C
Explanation:
BRAINLIEST PLS
Answer:
b
Explanation:
The answer is b.. because the charge of electrons is opposite to that of protons.. the combination of the equal number of protons and electrons has a total charge of zero(0)....
A wave with a frequency of 1.1 Hz travels through deep water at a speed of 5.7 m/s. When the wave enters shallow water, its speed slows to 3.2 m/s. What is the wavelength of the wave in the shallow water?
Answer:
The wavelength of the wave in shallow water is 2.91 m.
Explanation:
Given;
frequency of the wave, f = 1.1 Hz
speed of the wave in deep water, v₁ = 5.7 m/s
speed of the wave in shallow water, v₂ = 3.2 m/s
The wavelength of the wave in the deep water is calculated as;
λ₁ = v₁/f
λ₁ = 5.7 / 1.1
λ₁ = 5.18 m
The wavelength of the wave in the shallow water is calculated as;
λ₂ = v₂/f
λ₂ = 3.2 / 1.1
λ₂ = 2.91 m
Therefore, the wavelength of the wave in shallow water is 2.91 m.
Elements in Group____are common alkaline earth metals.
Answer here
Answer:
Explanation:
k
Answer:
Explanation:
Group 2 consists of the elements in the second column. They all have a combining number (valence number) of 2+ after giving away 2 electrons.They start with Beryllium (element 4 in the periodic table) and end with Radium (element 88 in the periodic table).A parallel plate capacitor of capacitance Co has plates of area A with separation d between them. When it is connected to a battery of voltage Vo, it has charge of magnitude Qo on its plates. It is then disconnected from the battery and the plates are pulled apart to a separation 2d without discharging them. After the plates are 2d apart, the new capacitance and the potential difference between the plates are: (Show all steps) [2 marks] a. ½ Co, ½ Vo b. ½ Co, 2Vo c. Co, Vo d. Co, 2Vo e. 2Co, 2Vo
Answer:
b. 1/2·C₀, 2·V₀
Explanation:
The capacitance on the parallel plate capacitor = C₀
The area of the plates = A
The voltage on the battery = V₀
The magnitude of the charge on the plate = Q₀
The new distance between the plates = 2·d
From an online physics source, we have;
[tex]C_0 = \epsilon_0 \times \dfrac{A}{d}[/tex]
Where;
ε₀ = Constant
A = The area of the plates
With the new distance, 2·d, we get;
[tex]C_{new} = \epsilon_0 \times \dfrac{A}{2\cdot d} = \dfrac{1}{2} \times \epsilon_0 \times \dfrac{A}{d} = \dfrac{1}{2} \times C_0[/tex]
Therefore;
[tex]The \ new \ capacitance \ C_{new} = \dfrac{1}{2} \times C_0[/tex]
The potential difference, 'V', is given as follows;
[tex]C = \dfrac{Q}{V}[/tex]
Therefore;
[tex]V = \dfrac{Q}{C}[/tex]
Given that Q = Q₀, we get;
[tex]V = \dfrac{Q_0}{\dfrac{1}{2} \times C_0} = 2 \times \dfrac{Q_0}{C_0} = 2 \times V_0[/tex]
∴ V = 2 × V₀
The new potential difference, V = 2·V₀
Therefore, after the plates are 2·d apart, the new capacitance and potential difference between the plates are;
1/2·C₀, 2·V₀.
At a distance of 2d, the potential difference will be twice the potential difference before while the capacitance will be half the value before.
Given to us
The capacitance on the parallel plate capacitor = C₀The area of the plate = AThe voltage on the battery = V₀The magnitude of the charge in the plate = Q₀The new distance between the plates = 2d What is Capacitance?We know capacitance can be written as,
[tex]C= \dfrac{\epsilon_0 A}{d}[/tex]
where C is the capacitance,
A is the area,
d is the distance and
ε₀ is the electrostatic constant,
Capacitance before,[tex]C= \dfrac{\epsilon_0 A}{d}[/tex]
Capacitance Afterwards,[tex]C= \dfrac{\epsilon_0 A}{2d}[/tex]
[tex]C=\dfrac{1}{2} \times \dfrac{\epsilon_0 A}{d}[/tex]
[tex]C=\dfrac{1}{2} \times C_0[/tex]
What is Voltage(Potential difference)?We know that for the voltage we can write,
[tex]\rm Voltage = \dfrac{Charge}{Capacitance}[/tex]
Voltage before[tex]V=\dfrac{Q_0}{C_0}[/tex]
Voltage Afterwards[tex]V_{new} = \dfrac{Q_0}{C_{new}}[/tex]
[tex]V_{new} = \dfrac{Q_0}{\dfrac{1}{2} \times C_0}[/tex]
[tex]V_{new} = 2 \times\dfrac{Q_0}{C_0}[/tex]
[tex]V_{new} = 2 \times V_0[/tex]
Hence, At a distance of 2d, the potential difference will be twice the potential difference before while the capacitance will be half the value before.
Learn more about Capacitance:
https://brainly.com/question/12356566
Energy can enter and exit which of the following systems?
A. Both open and close
B. Both open and isolated
C. Open Only
C. Isolated only
Answer:
A. Both open and close
Explanation:
just took the test
What is quantum, in your own words but be more detailed.
Answer: Quantum is really just an amount of any physical entity involved in an interaction.
Explanation:
A skydiver jumps from a stationary helicopter and reaches a steady vertical speed. She then opens her parachute. Which statement about the falling skydiver is correct?
A As her parachute opens, her acceleration is upwards.
B As she falls at a steady speed with her parachute open, her weight is zero.
C When she accelerates, the resultant force on her is zero.
alda
D When she falls at a steady speed, air resistance is zero.
Answer:
A) As her parachute opens, her acceleration is upwards.
Explanation:
The acceleration is the rate of change of the velocity.
Thus, if you have positive velocity and positive acceleration, your velocity increases
If you have positive velocity and negative acceleration, then your velocity decreases.
(The opposite happens when you have negative velocity).
Now, when the skydiver is falling, her velocity is downwards.
When she opens her parachute, her velocity downwards decreases.
This means that when she opens her parachute, she will have an acceleration in the opposite direction to her velocity, then at this point her acceleration is upwards.
We can conclude that the correct option is:
A) As her parachute opens, her acceleration is upwards.
Multiple Choice
Which is the best reason to be wary of those you talk to on the Internet?
A. They may not be who they say they are.
B. You don't know where they live.
C. You don't know their favorite foods.
D. They may not be in the same grade as you.
what factors could enhance memory and kept constant? and why
To help make sure information goes from short-term memory to long-term memory, you can use memory-enhancing strategies. One strategy is rehearsal, or the conscious repetition of information to be remembered. Think about how you learned your multiplication tables as a child.
Proven ways to protect memory include following a healthy diet, exercising regularly, not smoking, and keeping blood pressure, cholesterol, and blood sugar in check. Living a mentally active life is important, too. Just as muscles grow stronger with use, mental exercise helps keep mental skills and memory in tone.
According to one study, mental stimulation like reading can help protect memory and thinking skills, especially as you age. The authors even suggest that reading every day can slow down the late-life cognitive decline. ... The act of reading helps to heighten overall brain function and increase memory.
Let's take a deeper dive into evidence-based exercises that offer the best brain-boosting benefits.
Have fun with a jigsaw puzzle. ...
Try your hand at cards. ...
Build your vocabulary. ...
Dance your heart out. ...
Use all your senses. ...
Learn a new skill. ...
Teach a new skill to someone else. ...
Listen to or play music.
Un tanque de 50 litros tiene un gas a CNPT. ¿Cuánto valdrá la presión si la temperatura aumenta 40 °C, y el volumen permanece constante?
Answer:
La presion a 40 °C es 1.05 atm.
Explanation:
Usando la ecuación ideal de los gases.
[tex]PV=nRT[/tex]
Debemos recordar, que CNPT significa condiciones normales de presión y temperatura.
Para el primer estado tenemos:
[tex]P_{1}V_{1}=nRT_{1}[/tex]
Donde:
P(1) es la presion en el estado incial (1 atm)V(1) es el volumen incial (50 L)T(1) es la temperatura incial (25 °C = 298 K)Para el segundo estado:
[tex]P_{2}V_{2}=nRT_{2}[/tex]
Donde:
P(2) es la presion en el estado final ( x atm)V(2) es el volumen final (50 L)T(2) es la temperatura final (40 °C = 313 K)Como ambas ecuaciones tienen el mismo valor de volumen podemos igualarlas:
[tex]\frac{nRT_{1}}{P_{1}}=\frac{nRT_{2}}{P_{2}}[/tex]
n y R permanecen constantes, se puden cancelar.
[tex]\frac{T_{1}}{P_{1}}=\frac{T_{2}}{P_{2}}[/tex]
Despejamos P(2).
[tex]P_{2}=\frac{P_{1}T_{2}}{T_{1}}[/tex]
[tex]P_{2}=\frac{1*313}{298}[/tex]
[tex]P_{2}=1.05\: atm[/tex]
Espero te haya sido de ayuda!
What makes the results of a scientific experiment accurate? (5 points)
Answer:
A measurement is reliable if you repeat it and get the same or a similar answer over and over again, and an experiment is reliable if it gives the same result when you repeat the entire experiment.
Explanation:
Answer: when you repeat it and get the same results
Explanation:
When a scientist repeats an experiment with a different group of people or a different batch of the same chemicals and gets very similar results then those results are said to be reliable. Reliability is measured by a percentage – if you get exactly the same results every time then they are 100% reliable.