Supplied energy=300kJ
Wasted energy=70.5JUsed energy:-
[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]
We know
[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]
[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]
The overall efficiency of the electric car = 76.5 %
To find the efficiency the given values are:
Energy supplied = 300 kJ
Energy wasted = 70.5 kJ
Define efficiency and calculate the value of efficiency.In the system the output energy is compared to the input energy is known as efficiency. That can be written as percentage ratio of output energy to the input energy.
Formula of efficiency is,
Efficiency = ( E out / E in ) × 100
Here, Energy supplied = 300 kJ
so, energy used = Energy supplied - Energy wasted
= 300 - 70.5
= 229.5 kJ
Thus, substituting E out = 300 kJ , E in = 229.5 kJ
Efficiency = ( 229.5 / 300 ) ×100
= 229.5 / 3
= 76.5
Hence, The overall efficiency of the electric car is 76.5 %
Learn more about efficiency,
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how do u calculate the kinetic energy of a ball of mass 0.25kg being kicked vertically upwards with a speed of 5m/s
Answer:
3.125J
Explanation:
K.E.= 1/2(mass)(velocity)^2
K.E.=1/2(0.25)(5)^2=3.125
4. When setting goals, you should do everything EXCEPT which of the following?
Take into account your current level of activity.
Ask all of your friends what they think your goals should be..
Set a time limit.
Be realistic.
is placing a compass near a wire with live electrical current biology, chemistry, or physics?
The process of PLACING a compass wherever you want it involves Biology. Biology deals with everything that has to happen for your brain to send instructions to your muscles, your muscles to operate your arm and your hand, and your hand to move the compass to where you want it, while your eyes keep track of what's happening and send course-corrections through your brain.
Once you get the compass there and see it start doing strange things, those EFFECTS are explained by laws of nature that are covered in Physics.
Placing a compass near a wire with live electrical current involves physics. Because, the deflection in magnetic field by the current from the electrical wire is dealt with physics.
What is magnetic field ?A magnetic field is generated by the field lines originating from a magnet or an electrical coil. The moving current is always associated with a magnetic field.
A compass acts as a tiny magnet and it deflects to the north in the absence of an electrical field. If an electric field is brought in contact with the compass the needle will deflect into the direction of the magnetic field from the wire.
The strength of a magnetic field, associated electric field, magnetic flux etc. are more focused in the branches of physics. The magnetic properties of a substance is a physical property.
Find more on magnetic properties:
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A variable is a letter that stands in for a number and unit... True or False?
Why are road accidents at high speeds very much worse than road accidents at low speeds?
Answer:
The momentum makes it worse.
Explanation:
The momentum of vehicles running at faster speeds is very high and causes a lot of damage to the vehicles.
an electron is moving at 3.6 x 10^3 m/s. a photon with what wavelength would have the same momentum????
Answer:
The wavelength of the photon that would have the same momentum as the electron is 202.2180996 nm
Explanation:
The velocity of the electron, v = 3.6 × 10³ m/s
The momentum of an electron, [tex]p_e[/tex] = m × v
Where;
v = The mass of the electron = 9.109 × 10⁻³¹ kg
∴ [tex]p_e[/tex] = 9.109 × 10⁻³¹ kg × 3.6 × 10³ m/s = 3.27924 × 10⁻²⁷ kg·m/s
According to the de Broglie equation, the momentum of a photon, p, is given as follows;
p = h/λ
Where;
h = 6.63 × 10⁻³⁴ J·s
λ = The wavelength of the photon
∴ λ = h/p
According to the question, we have;
p = [tex]p_e[/tex] = 3.27924 × 10⁻²⁷ kg·m/s
∴ λ = 6.63 × 10⁻³⁴ J·s/(3.27924 × 10⁻²⁷ kg·m/s) = 2.02180993 × 10⁻⁷ m
The wavelength of the photon, λ = 2.02180993 × 10⁻⁷ m = 202.2180993 × 10⁻⁹ m = 202.2180993 nm.
A ball is dropped from the roof of a 25-m-tall building. What is the velocity of the object when it touches the ground? Suppose the ball is a perfect golf ball and it bounces such that the ve locity as it leaves the ground has the same magnitude but the op posite direction as the velocity with which it reached the ground How high will the ball bounce? Now suppose instead that the ball bounces back to a height of 20 m. What was the velocity with which it left the ground?
Answer:
a) [tex]h=25m[/tex]
b) [tex]v=19.8m/sec[/tex]
Explanation:
From the question we are told that:
Height [tex]h=25m[/tex]
Bounce Height [tex]h'=20m[/tex]
Generally the Kinematic equation is mathematically given by
[tex]V=\sqrt{2gh}\\\\V=\sqrt{2*9.81*25}[/tex]
[tex]V=22.1m/sec[/tex]
Therefore Height
[tex]h=\frac{V^2}{2g}\\\\h=\frac{22.1^2}{2*9.81}[/tex]
[tex]h=25m[/tex]
b)
Generally the Kinematic equation is mathematically given by
[tex]v^2=2ah[/tex]
[tex]v^2=2*9.8*20[/tex]
[tex]v=\sqrt{2*9.8*20}[/tex]
[tex]v=19.8m/sec[/tex]
In----- theory, the actual wishes that are threatening to the dreamers conscious awareness are disguised
Answer:
Unconscious wish fulfillment
Explanation:
Unconscious wish fulfillment
(In the unconscious wish fulfillment theory, the actual wishes of the dreamer that are threatening to the dreamer's conscious awareness are disguised.)
can anyone help me to explain theory of relativity???
Answer:
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.It applies to the cosmological and astrophysical realm, including astronomy.
The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves
Can someone pls help, thank you in advance!
What is an example of a force applied at an angle to displacement
Answer:
an object sliding down hill
Explanation:
On a slope, the force applied is due to gravity. Its direction is straight down. If the object is sliding down the hill, its displacement is at an angle to the applied force. The angle of displacement will depend on the steepness of the hill.
If 20N force produces an acceleration of 5ms^-2 In a body then the mass of the body will be:
A.4kg
B.5kg
C.1/4kg
D.1/5kg
Using your Periodic Table, which of the elements below is most likely to be a solid at room temperature?
A.) potassium, B.) Hydrogen, C.) Neon, D.) Chlorine
The answer is definitely Potassium
A car has a mass of 2000 kg. While it is traveling along a perfectly flat road, it goes around an unbanked turn that has a radius of 40.0 m. The coefficient of static friction between the car tires and the road is 0.500. The car travels successfully around the turn at a constant speed of 10.0 m/s. Calculate the magnitude of the car's acceleration as it goes around the turn. _______ m/s^2
Answer:
2.5 m/s²
Explanation:
The given parameters are;
The mass of the car, m = 2,000 kg
The radius of the car, r = 40.0 m
The coefficient of friction between the car tires and the road, μ = 0.500
The constant speed with which the car moves, v = 10.0 m/s
The normal reaction of the road on the car, N = The weight of the car;
∴ N = m × g
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
N ≈ 2,000 kg × 9.81 m/s² = 19,620 N
The frictional force, [tex]F_f[/tex] = μ × N
The centripetal force, [tex]F_c[/tex] = m·v²/r
The car moves without slipping when [tex]F_f[/tex] = [tex]F_c[/tex]
Therefore, [tex]F_f[/tex] = 0.500 × 19,620 N = 2,000 kg × [tex]v_{max}[/tex]²/40.0 m
∴ [tex]v_{max}[/tex] = √(0.500 × 19,620 N × 40.0 m/2,000 kg) ≈ 14.007 m/s
Therefore, the velocity with which the car moves, v < [tex]v_{max}[/tex]
The cars centripetal acceleration, [tex]a_c[/tex] = v²/r
∴ [tex]a_c[/tex] = (10.0 m/s)²/40.0 m = 2.5 m/s²
The cars centripetal acceleration as it goes round the turn, [tex]a_c[/tex] = 2.5 m/s².
A liquid has a density of 2 g/mL, the volume is measured at 20 mL, what is the mass of the liquid?
Answer: 40 grams, if it is two grams per mL and you have 20 mL, you multiply 2 grams/mL and you get the answer
what do you mean by scattering of light
Answer:
Scattering of light is the phenomenon in which light rays get deviated from its straight path on striking an obstacle like dust or gas molecules, water vapours etc. Scattering of light gives rise to many spectacular phenomena such as Tyndall effect and the “red hues of sunrise and sunset”.
Sort the processes based on the type of energy transfer they involve. condensation freezing deposition sublimation evaporation melting thermal energy added thermal energy removed
Answer:
condensation - thermal energy removed
freezing -thermal energy removed
deposition - thermal energy removed
sublimation - thermal energy added
evaporation - thermal energy added
melting - thermal energy added
Explanation:
Thermal energy is heat energy. Processes in which heat is added involve the addition of thermal energy while processes in which heat energy is removed involves removal of thermal energy.
Condensation involves a change from gas to liquid, freezing involves a change from liquid to solid while deposition involves the settling of mobile particles at a place. All these processes involve a decrease in energy of particles.
On the other hand, sublimation is a direct change from solid to gas, melting involves a change from solid to liquid while evaporation involves a change from liquid to gas. All these processes occur when energy is added to the particles in a system.
Answer:
condensation - thermal energy removed
freezing -thermal energy removed
deposition - thermal energy removed
sublimation - thermal energy added
evaporation - thermal energy added
melting - thermal energy added
how many significant figures 216 m
Answer:
Three
Explanation:
I hope this helps:)
give one example where friction is a hindrance.
Answer:
an example of when friction is a hindrance, is if someone with shorts is sliding down a slide. their skin rubbing on the slide will cause friction and will slow them down. another example is if you're dragging a large wooden box across the floor. the wood and the floor interacting cause friction and will make it more difficult to push the box.
Explanation:
hope this helps :D
how to find the mechanical advantage
Answer:
[tex]{ \bf{mechanical \: adv = \frac{load}{effort} }}[/tex]
A skipper on a boat notices wave crests passing his anchor chain every 5.6 s . He estimates the distance between wave crests to be 16 m . He also correctly estimates the speed of the waves. Find this speed.
Answer:
v = 2.85 m/s
Explanation:
Given that,
A skipper on a boat notices wave crests passing his anchor chain every 5.6 s.
The distance between wave crests to be 16 m.
We need to find the speed of the waves. The speed of a wave can be calculated by the formula as follows :
[tex]v=f\lambda\\\\v=\dfrac{\lambda}{T}\\\\v=\dfrac{16}{5.6}\\\\v=2.85\ m/s[/tex]
So, the speed of the wave is 2.85 m/s.
round off 20.96 to 3 significant figures. a.20.9 b.20 c.21.0 d.21
Answer:
option c. 21.0
Explanation:
It was given that to find 3 significant figures. So the answer is 21.0
2. ¿Puede haber trabajo en un sistema si no hay movimiento
a. Sí, si hay una fuerza siempre.
b. Sí, ya que el movimiento es sólo relativo.
c. No, ya que un sistema que no se mueve no tiene energía.
d. No, porque la ecuación de trabajo lo define.
Answer:
d. No, porque la ecuación de trabajo lo define.
Explanation:
En Física, el trabajo realizado se puede definir como la cantidad de energía transferida cuando un objeto o cuerpo se mueve a lo largo de una distancia debido a la acción de una fuerza externa.
Matemáticamente, el trabajo realizado viene dado por la fórmula;
[tex] W = F * d [/tex]
Dónde;
W es el trabajo realizado.F representa la fuerza que actúa sobre un cuerpo. d representa la distancia recorrida por el cuerpo.Por lo tanto, podemos deducir de la definición de trabajo y su fórmula que el trabajo se realiza cuando un objeto (cuerpo) se mueve una distancia o experimenta cualquier forma de desplazamiento mientras transfiere energía.
A cyclist goes round a circular path of circumference 343 m in s. The angle made by him, with the vertical is
WITH STEPS PLZ
you need the number of seconds to calculate the distance. I'm assuming that the seconds were written in the question but you forgot to write the here, you can calculate the distance then and find the exact point where the cyclist stopped since you have the circumference. then you can find the angle (after finding the distance he cycled) by subtracting it from 360 since the circular path will have an angle of 360 degrees.
Although your question lacks some data A general answer is provided :
The angle made vertically = 360° - x°
where x = angle at which the the cyclist stopped
and circumference of the circular path = Total Distance travelled by the cyclist
First step : determine the distance travelled by the cyclist vertically
circumference = 2*π*r
343 = 2*π * r
∴ r = 343 / ( 2π ) = 54.59
therefore distance travelled by the cyclist vertically = 54.59 * 2 = 109.18 m
Given that the time travelled is missing
assuming the angle to the distance travelled by the cyclist before it stopped vertically = 360° - x°
This is because the Total angle of a circular path = 360°
Learn more about circular paths : https://brainly.com/question/24210487
this is physics practical
Answer:
well done buddy
Explanation:
Using your Periodic Table, which element below has the smallest atomic radius? A.) Sodium, B.) Chlorine, C.) Phosphorus, D.) Iron
Chlorine has the smallest atomic radius since the atomic radius decreases as you travel to the right and up
An oscillator completes 240 cycles in 5.2 minutes.
Calculate its period (in seconds) and frequency (in Hz).
Answer:
I. Period = 1.3 seconds
II. Frequency = 0.769 Hertz
Explanation:
Given the following data;
Number of oscillation = 240 cycles
Time = 5.2 minutes.
Conversion:
1 minute = 60 seconds
5.2 minutes = X seconds
X = 60 * 5.2
X = 312 seconds
To find the following;
I. Period
Mathematically, the number of oscillation of a pendulum is given by the formula;
[tex] Number \; of \; oscillation = \frac {Time}{Period} [/tex]
Making period the subject of formula, we have;
[tex] Period = \frac {Time}{Number \; of \; oscillation} [/tex]
Substituting into the formula, we have;
[tex] Period = \frac {312}{240} [/tex]
Period = 1.3 seconds
II. Frequency
[tex] Frequency = \frac {1}{Period} [/tex]
Substituting the values into the formula, we have;
[tex] Frequency = \frac {1}{1.3} [/tex]
Frequency = 0.769 Hertz
You observe that you see more mockingbirds in small trees and more hawks in large trees. Which of the following is an appropriate scientific question based on this observation?
How does the size of a tree affect the bird species that prefer to live in it?
How do birds fly?
What type of food do birds eat?
What time of year to birds mate?
Answer:
A) How the size of a tree affect the bird species that prefer to live in it
Explanation:
I took the quiz
PRESS THE PHOTO NEED HELP!!! 30 POINTS
1:-
[tex]\\ \sf\longmapsto cos\Theta=\dfrac{B}{H}[/tex]
[tex]\\ \sf\longmapsto cos\Theta=\dfrac{4}{5}[/tex]
2:-
[tex]\\ \sf\longmapsto tan\Theta=\dfrac{P}{B}[/tex]
[tex]\\ \sf\longmapsto Tan\Theta=\dfrac{3}{4}[/tex]
Key Notes:-
P denotes to Perpendicular.B denotes to Base.H denotes to Hypotenuse.Answer:
Cos A = 4/5
Tan A = 3/4
Explanation:
Cos A = Adjacent/Hypotenuse = 4/5
Tan A = Opposite/Adjacent = 3/4
why Fossil fuel has been used more in the existing world ?
A object of mass 200kg is pushed from rest by a force of 500N along a horizontal plane for 5.0 seconds. Calculate the acceleration of the object
Answer:
force=mass×acceleration
hence
acceleration is given by force÷mass
(500÷200)*5=12.5
