Answer:
c
Explanation:
Answer:
C.
Explanation:
As global population ______
a.) increases b.) decreases
food production must _____
a.) increase b.) decrease
Answer:
As global population a.) increases food production must a.) increase.
Example:
More people means more food must be produced.
Which material is colder in a room where all the objects are in for a long time?
A. all objects are the same temperature
B. wooden desk
C. a metal chair
D. a smart board
Define Acceleration.
Ty!
Answer:
Acceleration is the name we give to any process where the velocity changes. Since velocity is a speed and a direction, there are only two ways for you to accelerate: change your speed or change your direction—or change both.
A train was moving at 50m/s and slow down to 20 m/s in 50 seconds, what was its acceleration?
Answer:
-0.6 m/s^2
Explanation:
a = change in velocity / time
change in velocity = 50 m/s - 20 m/s = 30 m/s
time = 50 s
30 m/s / 50s
= 0.6 m/s^2
because it is decelarating, it will be -0.6 m/s^2
Starting circuit One battery. 2 light bulbs in parallel; switch What is the voltage across the battery? What is the voltage across light bulb 1? What is the voltage across light bulb 2?
Answer:
The voltage across light bulb 1 and light bulb 2 is the the same i.e V
Explanation:
In a parallel circuit, the Voltage is same across all the components of the circuit and the current flowing through each component is added to get the total current across the circuit.
Let us say, the voltage across the circuit is V. The voltage across light bulb 1 and light bulb 2 is the the same i.e V
-1
9
5 points
An engine does 1421000 J of work to lift a beam 145 meters. How much force was exerted to lift the beam.
1566N
9800N
20445 N
50000N
Answer:
9800 N
Explanation:
applying,
W = Fd.................. Equation 1
Where W = work done by the engine, F = Force exterted to lift the beam, d = distance.
make F the subject of the equation
F = W/d............... Equation 2
From the question,
Given: W = 1421000 J, d = 145 meters.
Substitute these values into equation 2
F = 1421000/145
F = 9800 N
6. Which of the following statements is true for displacement ?
a. It cannot be zero
b. Its magnitude is more than the distance covered by the object.
Both are false..........
wait how does this work hehe this is kinda fun lol yay
Sound waves are blank waves
A) Longitudinal
B) mechanical
C) compression
D) all if the above
Para fabricar la bicicleta de un niño pequeño se tiene en cuenta que la fuerza que puede desarrollar es menor que la de un adulto y que no sabe cambiar de desarrollo. Por ello, se fabrica con un solo plato y un solo piñón de desarrollo muy pequeño. El plato es de 28 dientes y el radio de la rueda mide 20 cm. Si queremos que el desarrollo sea de 1,4 calcula: - El número de dientes que debe tener el piñón de la bicicleta. - Cuántos metros avanza la bicicleta por cada pedalada completa.
Answer:
a) El piñón debe tener 20 dientes.
b) La bicicleta avanza aproximadamente 1,759 metros por cada pedaleada completa.
Explanation:
a) El plato es el engranaje más grande que forma parte del sistema de transmisión, acompañando a la cadena y el piñón integrado a la rueda trasera. Asumiendo que no existen pérdidas por fricción seca y que las condiciones de lubricación del sistema de transmisión son óptimas tal que las pérdidas de potencia son despreciables. Además, supongamos que la bicicleta viaja a velocidad constante, entonces tenemos la siguiente identidad mediante las definiciones de trabajo y potencia:
[tex]T_{P}\cdot \omega_{P} = T_{p}\cdot \omega_{p}[/tex] (1)
Donde:
[tex]T_{P}[/tex] - Torque del plato, en newton-metros.
[tex]T_{p}[/tex] - Torque del piñón, en newton-metros.
[tex]\omega_{p}[/tex] - Rapidez angular del piñón, en radianes por segundo.
[tex]\omega_{P}[/tex] - Rapidez angular del plato, en radianes por segundo.
Sabiendo el hecho que tanto el plato y el piñón experimenta la misma velocidad tangencial, podemos simplificar (1) como sigue:
[tex]\frac{T_{P}}{R_{P}} = \frac{T_{p}}{R_{p}}[/tex] (1b)
Puesto que el radio de cada elemento y el número de dientes son, por separado, directamente proporcionales al número de dientes, modificamos (1b) así y tenemos la siguiente identidad, la cual equivale a su vez a la razón de desarrollo:
[tex]\frac{T_{P}}{T_{p}} = \frac{N_{P}}{N_{p}} = \frac{R_{P}}{R_{p}} = \frac{\omega_{p}}{\omega_{P}}[/tex] (1c)
Donde:
[tex]N_{p}[/tex] - Número de dientes del piñón, sin unidad.
[tex]N_{P}[/tex] - Número de dientes del plato, sin unidad.
Si tenemos que [tex]r = 1,4[/tex] y [tex]N_{P} = 28[/tex], entonces tenemos que el número de dientes del piñón es:
[tex]r = \frac{N_{P}}{N_{p}}[/tex]
[tex]N_{p} = \frac{N_{P}}{r}[/tex]
[tex]N_{p} = \frac{28}{1,4}[/tex]
[tex]N_{p} = 20[/tex]
El piñón debe tener 20 dientes.
b) De acuerdo con la relación de desarrollo, por cada revolución realizada por el plato, el piñón realiza 1,4 revoluciones. Entonces, el avance realizado por la rueda trasera ([tex]s[/tex]), en metros, es igual al productor de la relación de desarrollo y la circunferencia de la rueda, es decir:
[tex]s = r\cdot 2\pi\cdot R[/tex] (1)
Donde [tex]R[/tex] es el radio de la rueda trasera, en metros.
Si conocemos que [tex]r = 1,4[/tex] y [tex]R = 0,2\,m[/tex], entonces el avance realizado por la rueda trasera es:
[tex]s = r\cdot 2\pi\cdot R[/tex]
[tex]s = (1,4)\cdot (2\pi)\cdot (0,2\,m)[/tex]
[tex]s \approx 1,759 \,m[/tex]
La bicicleta avanza aproximadamente 1,759 metros por cada pedaleada completa.
NEED HELP A 400 Ω resistor is connected across 200 V. What current will flow?Single choice.
(2 Points)
0.25 A
0.5 A
2.0 A
4.0 A
Answer: 0.5A
Explanation:
According to Ohm's law, the Voltage(V) when a current flows through a resistor can be calculated by using the formula:
V = IR
where,
V = Voltage = 200V
I = current in amps (A)
R = resistance in ohms (Ω) = 400Ω
Current = Voltage / Resistance
I = V/R
I = 200/400
I = 0.5A
Therefore, the current is 0.5 Ampere
Question 4
The diagram represents the motion of a sound wave. The distance between points A and C is 9 meters (m), and it initially takes the wave 3 seconds (s) to travel.
What will be the wavelength of the sound wave if the velocity of the wave remains constant but the pitch is tripled?
A 3 meters
B 6 meters
с 9 meters
D 18 meters
Answer:A
Explanation:
The wavelength of the sound wave will be 3 meters.
What is wavelength?
The wavelength of any wave is defined as the distance between two max adjacent amplitudes, or the distance between two successive troughs or crest.
Now it is given that:
Distance =9 meters
time = 3 seconds
pitch=1/3 seconds
The velocity of the sound will be
[tex]V=\dfrac{d}{t}=\dfrac{9}{3}=3\ \frac{m}{s}[/tex]
Now from the question the wavelength of the sound wave if the velocity of the wave remains constant but the pitch is tripled
so [tex]f=3\times \dfrac{1}{3}=1 herts[/tex]
Now the velocity of the sound will be
[tex]v=f\times \lambda[/tex]
[tex]\lambda=\dfrac{v}{f}=\dfrac{3}{1}=3\ m[/tex]
Thus the wavelength of the sound wave will be 3 meters.
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Which geologic events occur most often at this mid-oceanic ridge plate
boundary? *
2 points
Mid-oceanic ridge
plate boundary
Shelf
Sea level
Patella
Plate 2
Continental
crust
Rigid mantle
Asthenosphere
magnetic pole reversals and cooling of ocean water
hydrospheric pollution and adiabatic heating
earthquakes and volcanic eruptions
Answer: Earthquakes and Volcanic eruptions
Explanation:
You did not attach a picture however, this should be the correct answer.
Mid-oceanic ridge plate boundaries such as the Mid-Atlantic Ridge form as a result of plate separating at the boundary. This leads to earthquakes due to the forces of tension acting on the plates.
When this happens, the mantle is exposed and therefore there will be volcanic eruptions as the lava comes to the surface as magma. When this magma cools it creates new seafloors and underwater mountains.
Science Check: Light Waves and Their Behavior 4 of 104 of 10 Items Question POSSIBLE POINTS: 1 Why is a light wave not considered a matter wave? A light wave is visible to humans. A light wave is visible to humans. A light wave moves faster than most waves. A light wave moves faster than most waves. A light wave does not have a wave length. A light wave does not have a wave length. A light wave travels through the vacuum of space. A light wave travels through the vacuum of space.
Answer:
A light wave travels through the vacuum of space
Explanation:
A light wave cannot be a matter wave because a matter wave is made up of
atoms while light wave is a form of radiation (electromagnetic). A matter wave requires a medium to travel while a light wave do not require medium to travel. Since light wave is a form of radiation, light can travel in vacuum.
Hence, the correct answer is A light wave travels through the vacuum of space
All mutations are favorable and increase the ability for the
organism's offspring to survive.
TRUE
FALSE
A teacher performing a demonstration finds that a piece of cork displaces 23.5 cm3 of water. The piece of cork has a mass of 5.7 g. What is the density of the cork
Answer:
Density = 0.243 g/cm³
Explanation:
Volume of cork = 23.5 cm³
Mass = 5.7 g
To find the density of the cork;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the formula;
[tex]Density = \frac{mass}{volume}[/tex]
Substituting into the formula, we have;
Density = 5.7/23.5
Density = 0.243 g/cm³
What is the power of a hair dryer with a current of 4 A and a resistance of 60 ohms?
Answer:
960W
Explanation:
v=R×I
v=60ohm.4A=240v
p=VI
p=240v.4A
p=960W
The power of a hair dryer with a current of 4 A and a resistance of 60 ohms is 960 W.
What is power?
The amount of work completed in a given amount of time. Watt (W), which is derived from joules per second (J/s), is the SI unit of power. Horsepower (hp), which is roughly equivalent to 745.7 watts, is a unit of measurement sometimes used to describe the power of motor vehicles and other devices.
Given in the question a hair dryer with a current of 4 A and a resistance of 60 ohms power, p
Voltage, v=R×I
v=60 ohm.4 A=240 v
power, p=VI
p=240 v.4 A
p=960 W
The power of a hair dryer with a current of 4 A and a resistance of 60 ohms is 960 W.
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Which of the following is an example of uniform circular motion?
A. Swinging on a swing
B. Spinning on a merry-go-round
C. Sliding down a slide
D. Bouncing on a trampoline
Answer:
B
Explanation:
First narrow answers to CIRCULAR motion.
Only A and B have circular motion.
Second look at the keyword UNIFORM. A swing does not have uniform motion because it will accelerate due to gravity and have the most velocity at the bottom of the swing.
Therefore, it must be B.
This graph shows how the reaction rate of a chemical reaction changed as concentration of reactant changed. Which sentence best describes how the reaction rate changed.
Answer:
A
Explanation:
The Reaction rate is going down which is why its at 0 And the concetration line is going up which means increasing,
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.
Which of the following is TRUE about thermal equilibrium?
Answer:
option one
Explanation:
equilibrium is used to describe the point in which something meets in this case the temperature of an object
what does the slope of a velocity-time graph reveal about an objects motion
Answer:
The slope of a velocity graph represents the acceleration of the object. So, the value of the slope at a particular time represents the acceleration of the object at that instant.
Answer:
The slope of a velocity graph represents the acceleration of the object.
Explanation:
So, the value of the slope at a particular time represents the acceleration of the object at that instant.
Genes consist of portions of ______.
What is the baseball's mechanical energy when it is at a height of 8.0 m? Explain.
Answer:
In this section, we elaborate and extend the result we derived in Potential Energy of a System, where we re-wrote the work-energy theorem in terms of the change in the kinetic and potential energies of a particle. This will lead us to a discussion of the important principle of the conservation of mechanical energy. As you continue to examine other topics in physics, in later chapters of this book, you will see how this conservation law is generalized to encompass other types of energy and energy transfers. The last section of this chapter provides a preview.
The terms ‘conserved quantity’ and ‘conservation law’ have specific, scientific meanings in physics, which are different from the everyday meanings associated with the use of these words. (The same comment is also true about the scientific and everyday uses of the word ‘work.’) In everyday usage, you could conserve water by not using it, or by using less of it, or by re-using it. Water is composed of molecules consisting of two atoms of hydrogen and one of oxygen. Bring these atoms together to form a molecule and you create water; dissociate the atoms in such a molecule and you destroy water. However, in scientific usage, a conserved quantity for a system stays constant, changes by a definite amount that is transferred to other systems, and/or is converted into other forms of that quantity. A conserved quantity, in the scientific sense, can be transformed, but not strictly created or destroyed. Thus, there is no physical law of conservation of water.
Systems with a Single Particle or Object
We first consider a system with a single particle or object. Returning to our development of (Figure), recall that we first separated all the forces acting on a particle into conservative and non-conservative types, and wrote the work done by each type of force as a separate term in the work-energy theorem. We then replaced the work done by the conservative forces by the change in the potential energy of the particle, combining it with the change in the particle’s kinetic energy to get (Figure). Now, we write this equation without the middle step and define the sum of the kinetic and potential energies, K+U=E; to be the mechanical energy of the particle
which instrument determine the purity of milk
Answer:
Milk Lactometer
Milk Lactometer: A lactometer is an instrument that is used to check for the purity of milk by measuring its density.
lactometer is used to determine the purity of milk
hope it is helpful to you
The image shows street lights powered by solar panels. Which sequence shows the energy transformations taking place in these lights?
A.
gravitational potential energy → vibrational energy → chemical potential energy
B.
radiant energy → chemical potential energy → motion energy
C.
radiant energy → electric energy → radiant energy
D.
sound energy → chemical potential energy → radiant energy
E.
gravitational potential energy → motion energy → radiant energy
Answer:
the answer is c
Explanation:
i did the test
Amos runs up a flight of stairs with a. total change in energy E. Vanessa exerts double the amount of energy in twice the time. How does Amos power output, Pa compare with Vanessa's power output, Pv?
Answer: Pa=Pv
Explanation:
Khan academy
Amos runs up a flight of stairs with a total change in energy ΔEA. Vanessa exerts double the amount of energy in twice the time.
How does Amos’s power output, PA, compare with Vanessa’s power output, Pv?
Answer: Pa=Pv
An electric circuit consists of light bulb with resistance of 10.0 ohm is connected to a
voltage source. The source provides a current of 2.00 mA in the bulb. What is the power
of the light bulb?
Answer:
P=I²R
Explanation:
P=2*10^-3 square times 10
4 times ten raise to power minus 5
relative density of a solid is 2.5 if its volume is 7.5 m³and then find its mass
hope it is helpful to you
An object is dropped without initial speed
from a height of 20 m above ground and falls
with a constant acceleration of 10 m.s-2.
a. How long does it take the object to
reach the ground?
b. What is its speed upon reaching
ground?
Answer:
a. t = 2 s
b. vf = 20 m/s
Explanation:
a.
We can the second equation of motion to find out the time to reach the ground:
[tex]h = v_it + \frac{1}{2}at^2[/tex]
where,
h = height = 20 m
vi = initial velocity = 0 m/s
t = time taken to reach the ground = ?
a = acceleration = 10 m/s²
Therefore,
[tex]20\ m = (0\ m/s)t+\frac{1}{2} (10\ m/s^2)t^2\\\\t^2 = \frac{20\ m}{5\ m/s^2}\\\\t = \sqrt{4\ s^2}[/tex]
t = 2 s
b.
Here, we will use the first equation of motion to find the final speed:
[tex]v_f = v_i + at\\v_f = 0\ m/s + (10\ m/s^2)(2\ s)[/tex]
vf = 20 m/s