Answer:
yes.................
The electric motor of an elevator(lift) uses 630kJ of electric energy when raising the elevator and passengers, of total mass 12,500N, through a vertical height of 29m.Calculate the efficiency of the elevator. pppppplease need helpp willl markk the brrainliest
Answer:
Efficiency = 0.575 = 57.5%
Explanation:
First, we will calculate the output energy of the elevator, which is equal to the potential energy acquired by the load.
[tex]O = Potential\ Energy\\O = mgh[/tex]
where,
O = Output = ?
mg = W = Weight = 12500 N
h = height = 29 m
Therefore,
[tex]O = (12500\ N)(29\ m) \\O = 362500\ J = 362.5\ KJ[/tex]
The input is given as:
I = 630 KJ
Thus the efficiency will be:
[tex]Efficiency = \frac{O}{I} = \frac{362.5\ KJ}{630\ KJ}\\\\[/tex]
Efficiency = 0.575 = 57.5%
If a 20kg ball is sitting at rest on the top of a 100m hill, what it the velocity of the ball when it rolls down the hill and is 10m from the bottom? Show, at least, your final calculation.
Answer:
Explanation:
This is the First Law of Thermodynamics that says that energy cannot be created nor destroyed. Which means, to us, that the ball has a specific amount of energy available to it, regardless of where it is in its travels, and this amount of energy will never be increased or decreased, that it will ust change its form. The Total Energy equation for this situation is
TE = PE + KE whih says that the total energy available to the system is equal to its Potential Energy plus its Kinetic Energy, and that Total Energy will never change. First we need to find the TE available. Looking at the first statement, we come into this problem and the ball is sitting still at the top of a hill. If the ball is sitting still, it has no Kinetic Energy, so all the energy is Potential. Therefore,
TE = PE + 0 and what we find here for the TE is the TE available throughout the trip. PE = mgh, so
TE = (20.0)(9.8)(100.0) I added in some sig dig but will still round to 2 because 1 does nothing for us.
TE = 2.0 × 10⁴ J. Now we move on to the next part of the problem, where the ball starts moving. The instant the ball starts moving, the PE starts to convert to KE, but as long as the ball still has the potential to fall to a lesser height, it also still has PE...long story short, it has both PE and KE at this point. And since TE = PE + KE, then
2.0 × 10⁴ = (20.0)(9.8)(10.0) + [tex]\frac{1}{2}(20.0)v^2[/tex] and we solve for v, simplifying some at first.
2.0 × 10⁴ = 2.0 × 10³ + 10.0v² and
[tex]v=\sqrt{\frac{2.0*10^4-2.0*10^3}{10.0} }[/tex] so, to 2 sig fig,
v = 42 m/s
Get to know how to do this; it will save your sanity!!
On the graph of voltage versus current, which line represents a 3.0 ohm
resistor?
Will give brainliest
Answer:
D. Graph A
Explanation:
Ohm's law states that V = I*R
So rearrange the equation by dividing the Volts by the amps to give you resistance.
R = 12/4
R = 3 ohm
The line in graph of voltage versus current, which represents a 3.0 ohm
resistor is line A. The correct option is D.
What is current?The current is the stream of charges which flow inside the conductors when connected across the end of voltage.
Given, the graph of voltage versus current is given.
From the graph, I = 4A and V= 12 V
From the Ohm's law, V =IR
Resistance, R = V/I
By substituting the values, we get
R = 12/4
R= 3 ohms
The resistance of the circuit, 3 ohm is represented by the line A on the graph.
Thus, the correct option is D.
Learn more about current.
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The diagram shows a stone tied to a string in circular
motion. If the string breaks, what will be the direction of
motion of the stone?
Answer:
Newton's First Law of motion states that an object will continue to move in a straight line or remain at rest unless a force acts on it
The stone is able to move in circular motion because a (centripetal) force acts through the string on it, which maintains the circular motion, by turning the stone to the circular path as the stone moves with momentary velocity along a straight line which is (therefore) tangential to the circle
Therefore, at the point the spring breaks, the centripetal force is no longer acting on the stone to change its path and the motion of the continues on the tangent to the initial circular motion path at that point
Explanation:
Which types of forces exist between the two protons in a helium nucleus?
1.
a repulsive electrostatic force and a repulsive gravitational force
2.
a repulsive electrostatic force and an attractive strong nuclear force
3.
an attractive electrostatic force and an attractive gravitational force
4.
an attractive electrostatic force and an attractive strong nuclear force
Answer:
Option (2) is correct.
Explanation:
When two charges have equal charges they repel each other. On the other hand, if they have unequal charges they attract each other.
The force between the two protons in a helium nucleus is electrostatic charges and the force is repulsive in nature.
Also, there exists a strong nuclear force between charges.
So, a repulsive electrostatic force and an attractive strong nuclear force is the correct answer.
What is electric potential
Answer:
The amount of work need to move a unit charge from a reference point to a specific point against an electric field.
What is latent heat?
A.
energy released or absorbed to change the kinetic energy of a substance
B.
energy released or absorbed to change the pressure of a substance
C.
energy released or absorbed to change the temperature of a substance
D.
energy released or absorbed to change the phase of a substance
a. An object takes 5 s to reach the
ground from a height of 5 m on a
planet. What is the value of g on the
planet?
Ans: 0.4 m/s2
Answer:
g = 0.4 m/s²
Explanation:
Given the following data;
Height = 5 meters
Time = 5 seconds
To find the acceleration due to gravity (g) on the planet;
Mathematically, the maximum height of an object is given by the formula;
H = ½gt²
Where;
H is the height measured in meters.
g is the acceleration due to gravity.
t is time measured in seconds.
Substituting into the formula, we have;
5 = ½ * g * 5²
5 = 0.5 * g * 25
5 = 12.5 * g
g = 5/12.5
g = 0.4 m/s²
HELPpPpo ASAP
Which statements about acceleration are true?
Check all that apply.
O A. To calculate acceleration, divide the change in velocity by the
change in time.
B. The symbol for acceleration is a
c. For acceleration, you must have a number, a unit, and a direction.
O D. The SI units for acceleration are miles per hour per second.
Answer:
Explanation:
The only one NOT true is D. The label for acceleration is meters/sec/sec or
[tex]\frac{m}{s^2}[/tex]
12 Write a difference between FPS
and CGS unit system of unit.
Answer:
CGS means Centimeter Gram Second while FPS means Foot Pounds Second
Explanation:
FPS is the standard used to measurement of length, mass and time. The unit of length is foot.
The time is calculated as the unit of seconds. CGS is the measurement of length, mass and time in units of centimeter, gram and second respectively
why must geostationary satellite rotate in the same direction as Earth's rotation?
Answer:
Its happen because the satellite orbits at the same speed as the Earth is rotating, so it appears that the satellite is located at the same longitude, although it may drift from north to south. This particular, high Earth orbit is called geosynchronous. It is always directly in the same place on the surface of the earth.
Explanation:
•| jess bregoli |•#keep learning!!
PLEASE HELP WITH THIS QUESTION
The reason you should always wear your seatbelt in a moving car
A. Newton's 1st law
B. Newton's 2nd law
C. Newton's 3rd law
Who was Sir Isaac Newton? Be sure to explain in your own words.
Answer:
the person who invented gravity
Explanation:
newton was a mathmaticians when one day an apple fell on him. he had the idea to name the force gravity. While he "made" gravity he made other important laws the 3 newton laws of physics
Answer:
Issac Newton was around in the 1600s and early 1700s and is a very important mathematician and invented calculus.
Explanation:
is driving with a velocity of 5 m/s and speeds up to a velocity of 10 m/s over 5 seconds. What is Mr. DaCosta's acceleration?
How many significant digits does 40.60 have?
physics
Answer: 4
Explanation:
Answer:
4
Explanation:
How does a country qualify for this sport for the Summer Olympic games?
Answer:
The top-15 world-ranked players will be eligible for the Olympics, with a limit of four players from a given country. Beyond the top 15, players will be eligible based on the world rankings, with a maximum of two eligible players from each country that does not already have two or more players among the top-15.
1 Diagram 1 shows an experiment to prove the existence
of electric fields. The two electrodes are connected to a
very high voltage
(a) Why is cooking oil used?
elect
11 mark]
23
Answer:
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PLS HELP ME
How does one stage in a stars life lead to another
A 5.20-N force is applied to a 1.05-kg object to accelerate it rightwards. The object encounters 3.29-N of friction. Determine the acceleration of the object.
Answer:
Explanation:
We will use the equation F - f = ma, which is just a fancy way of stating Newton's 2nd Law. For us:
F = 5.20 to the right (+)
f = 3.29 to the left (-)
m = 1.05 kg. Therefore,
5.20 - 3.29 = 1.05a and
1.91 = 1.05a so
a = 1.82 m/s/s to the right
Enunciado del ejercicio n° 1
Se lanza un cuerpo verticalmente hacia abajo con una velocidad inicial de 7 m/s.
a) ¿Cuál será su velocidad luego de haber descendido 3 s?
b) ¿Qué distancia habrá descendido en esos 3 s?
c) ¿Cuál será su velocidad después de haber descendido 14 m?
d) Si el cuerpo se lanzó desde una altura de 200 m, ¿en cuánto tiempo alcanzará el suelo?
e) ¿Con qué velocidad lo hará?
Usar g = 10 m/s²
Desarrollo
Datos:
v0 = 7 m/s
t = 3 s
y = 200 m
h = 14 m
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 2
Se lanza un cuerpo verticalmente hacia arriba con una velocidad inicial de 100 m/s, luego de 4 s de efectuado el lanzamiento su velocidad es de 60 m/s.
a) ¿Cuál es la altura máxima alcanzada?
b) ¿En qué tiempo recorre el móvil esa distancia?
c) ¿Cuánto tarda en volver al punto de partida desde que se lo lanzo?
d) ¿Cuánto tarda en alcanzar alturas de 300 m y 600 m?
Usar g = 10 m/s²
Desarrollo
Datos:
v0 = 100 m/s
vf = 60 m/s
t = 4 s
y1 = 300 m
y2 = 600 m
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 3
Un observador situado a 40 m de altura ve pasar un cuerpo hacia arriba con una cierta velocidad y al cabo de 10 s lo ve pasar hacia abajo, con una velocidad igual en módulo pero de distinto sentido.
a) ¿Cuál fue la velocidad inicial del móvil?
b) ¿Cuál fue la altura máxima alcanzada?
Usar g = 10 m/s²
Desarrollo
Datos:
t = 10 s
y = 40 m
Fórmulas:
(1) vf = v0 + g·t
(2) y = y0 + v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 4
Desde un 5° piso de un edificio se arroja una piedra verticalmente hacia arriba con una velocidad de 90 km/h, ¿cuánto tardará en llegar a la altura máxima?
Usar g = 10 m/s²
Desarrollo
Datos:
v0 = 90 km/h
v0 = 25 m/s
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 5
Un auto choca a 60 km/h contra una pared sólida, ¿desde qué altura habría que dejarlo caer para producir el mismo efecto?
Usar g = 10 m/s²
Desarrollo
Datos:
vf = 60 km/h
vf = 16,67 m/s
v0 = 0 m/s
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 6
Se lanza una pelota hacia arriba y se recoge a los 2 s, calcular:
a) ¿Con qué velocidad fue lanzada?
b) ¿Qué altura alcanzó?
Usar g = 10 m/s²
Desarrollo
Datos:
t = 2 s
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 7
Se lanza una pelota de tenis hacia abajo desde una torre con una velocidad de 5 m/s.
a) ¿Qué velocidad tendrá la pelota al cabo de 7 s?
b) ¿Qué espacio habrá recorrido en ese tiempo?
Usar g = 10 m/s²
Desarrollo
Datos:
v0 = 5 m/s
t = 7 s
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 8
Se lanza un cuerpo verticalmente hacia arriba con una velocidad de 60 km/h, se desea saber la altura máxima alcanzada, la velocidad que posee al cabo de 4 s y 30 s, la altura alcanzada a los 8 s, el tiempo total que se encuentra en el aire.
Desarrollo
Datos:
v0 = 60 km/h = (60 km/h)·(1.000 m/km)·(1 h/3.600 s) = 16,67 m/s
t1 = 4 s
t2 = 30 s
t3 = 8 s
Usar g = 10 m/s²
Fórmulas:
(1) vf = v0 + g·t
(2) y = v0·t + ½·g·t²
(3) vf² - v0² = 2·g·h
Enunciado del ejercicio n° 9
Se dispara verticalmente hacia arriba un objeto desde una altura de 60 m y se observa que emplea 10 s en llegar al suelo. ¿Con que velocidad se lanzo el objeto?
Desarrollo
Datos:
h0 = 60 m
t = 10 s
g = 9,81 m/s²
Fórmulas:
Δy = v0·t + ½·g·t²
Enunciado del ejercicio n° 10
Se lanza verticalmente hacia abajo una piedra de la parte alta de un edificio de 14 pisos, llega al suelo en 1,5 s, tomando en cuenta que cada piso mide 2,6 m de altura. Calcular la velocidad inicial de la piedra y la velocidad al llegar al piso.
Desarrollo
Datos:
Número de pisos = 14
Altura de cada piso = 2,6 m
t = 1,5 s
g = 9,81 m/s²
Fórmulas:
1) Δh = v0·t + ½·g·t²
2) vf = v0 + g·t
*xfv se que es mucho pero e visto videos pero no me sale muy bien los resultados con mis compañeros. xfv alguien que me ayude
Answer:
34
Explanation:
A park ranger driving on a back country road suddenly sees a deer in his headlights 20
m ahead. The ranger, who is driving at 11.4 m/s, immediately applies the brakes and
slows down with an acceleration of 3.80 m/s2. How much distance is required for the
ranger's vehicle to come to rest? Only enter the number, not the units.
Answer:
17.1
Explanation:
The distance ahead, of the deer when it is sighted by the park ranger, d = 20 m
The initial speed with which the ranger was driving, u = 11.4 m/s
The acceleration rate with which the ranger slows down, a = (-)3.80 m/s² (For a vehicle slowing down, the acceleration is negative)
The distance required for the ranger to come to rest, s = Required
The kinematic equation of motion that can be used to find the distance the ranger's vehicle travels before coming to rest (the distance 's'), is given as follows;
v² = u² + 2·a·s
∴ s = (v² - u²)/(2·a)
Where;
v = The final velocity = 0 m/s (the vehicle comes to rest (stops))
Plugging in the values for 'v', 'u', and 'a', gives;
s = (0² - 11.4²)/(2 × -3.8) = 17.1
The distance the required for the ranger's vehicle to com to rest, s = 17.1 (meters).
In which of the following is there more than one path for electrons to flow?
A.An open Circuit
B.A parallel circuit
C.A series circuit
D.A closed circuit
B
because in parallel combination there are more than one paths for the current to flow .
How to solve the equation of power ?
Answer:
OK HERE
Explanation:
When raising a power to a power in an exponential expression, you find the new power by multiplying the two powers together. For example, in the following expression, x to the power of 3 is being raised to the power of 6, and so you would multiply 3 and 6 to find the new power.
El peso(w) de una persona en la Tierra es 550N. Determinar la masa (m) de la persona y el peso (w) de la misma en la Luna
The question is: The weight (w) of a person on Earth is 550N. Determine the mass (m) of the person and the weight (w) of the person on the Moon.
Answer: The mass (m) of the person is 550 N and the weight (w) of the person on the Moon is 891 kg.
Explanation:
Given: Mass = 550 N
When a person moves towards moon then its mass will remain the same but there will occur change in its weight because the acceleration due to gravity on moon is different than that on Earth.
Therefore, formula used to calculate the weight of person on moon is as follows.
[tex]W = m \times g_{m}[/tex]
where,
m = mass
[tex]g_{m}[/tex] = acceleration due to gravity on moon = 1.62 [tex]m/s^{2}[/tex]
Substitute the values into above formula as follows.
[tex]W = m \times g_{m}\\= 550 N \times 1.62 m/s^{2}\\ (1 N = 1 kg \times m/s^{2})\\= 891 kg[/tex]
Thus, we can conclude that the mass (m) of the person is 550 N and the weight (w) of the person on the Moon is 891 kg.
A satellite orbits the earth with a kinetic energy of 2.0 x 10^10 J. Its gravitational potential energy
in this orbit is -4.0 x 10^10 J. What is the total energy of the satellite (relative to infinity)?
0 -6.0 x 10^10 J
O 6.0 x 10^10 J
0-2.0 x 10^10 J
O 2.0 x 10^10 J
Answer:
the total energy of the satellite is -2.0 x 10¹⁰ J
Explanation:
Given;
kinetic energy of the satellite, K.E = 2.0 x 10¹⁰ J
gravitational potential energy, P.E = -4 x 10¹⁰ J
The total mechanical energy of the satellite is calculated as follows;
M.E = K.E + P.E
M.E = 2.0 x 10¹⁰ J - 4 x 10¹⁰ J
M.E = -2.0 x 10¹⁰ J
Therefore, the total energy of the satellite is -2.0 x 10¹⁰ J
Si se desea construir un circuito con poca resistencia se debe colocar: En serie Mixto Paralelo Ninguna de las anteriores
Answer:
Parallel combination
Explanation:
When the two resistances are connected in parallel then the equivalent resistance is
[tex]\frac{1}{R}=\frac{1}{R'}+\frac{1}{R''}[/tex]
To get the minimum resistance of a circuit, the circuit components should be connected in parallel combination.
In the parallel combination, the voltage across each resistor is same and the current is divided in every resistance according to the resistances.
A 0.1 kg popper is placed on a table. When it pops
up, it reaches a height of 2.0 meters. What was the
initial velocity of the popper off the table?
Answer:
The initial velocity of the pooper off the table is approximately 9.264 m/s
Explanation:
The mass of the popper, m = 0.1 kg
The height the popper reaches, h = 2.0 meters
The initial velocity of the popper, 'u', is given by the following kinematic relation;
v² = u² - 2·g·h
Where;
h = The height the popper reaches = 2.0 m
v = The final velocity of the popper at the height it reached = 0 m/s
u = The initial velocity of the pooper off the table
g = The acceleration du to gravity, g ≈ 9.81 m/s²
Plugging in the values gives;
0² = u² - 2 × 9.81 × 2.0
∴ u - √(2 × 9.81 × 2.0) ≈ 9.264
The initial velocity of the pooper off the table, u ≈ 9.264 m/s.
2. 2. A drawing that shows the outline of an object is called
what is the maximum density of water
Answer:
4ºC or 39.2ºF
assume that you have three electrically charged body 'a' and body 'b' attract body 'c'. what is the sign of the charge of each body?
Answer: Sign of body 'a' is + and body 'b' & 'c' is -
Hope this answer is right!
Explanation:
The same charge repels each other and the opposite charge attracts each other. The force between the same charge is called repulsive charge and that of opposite charge is called attractive charge. The bodies A and B repel each other, so the charge of the body A and body B is of the same nature.
