This question is incomplete, the complete question is;
A 1800 kg hybrid vehicle operates on ethanol and is equipped with a multipurpose motorgenerator-flywheel. When the vehicle slows or stops, 50% of the kinetic energy is recovered as electrical energy in the battery. When the IC engine is used to recharge the battery, there is a 25% efficiency of converting chemical energy in the fuel to electrical energy stored in the battery. The vehicle slows from 70 miles per hour to 20 miles per hour. Calculate: (A) Electrical energy recovered in the battery in [kJ] (B) Mass of fuel needed to store same amount of energy in the battery in [kg]
Answer:
a) Electrical energy recovered in the battery is 404.6895 kJ
b) Mass of fuel needed to store same amount of energy in the battery is 0.0606 kg
Explanation:
Given that;
Initial speed of the vehicle V = 70 miles per hour = 31.293 m/s
Final speed of the vehicle u = 20 miles per hour = 8.941 m/s
mass of vehicle m = 1800 kg
Noe, change in kinetic energy of the vehicle will be;
[tex]E_{kinetic}[/tex] = [tex]\frac{1}{2}[/tex]m( v² - u² )
we substitute
= [tex]\frac{1}{2}[/tex] × 1800( (31.293)² - (8.941)² )
= 900( 979.2518 - 79.9414)
= 900 × 899.3104
= 809379.36 J
[tex]E_{kinetic}[/tex] = 809.379 kJ
now, Electrical energy recovered in the battery when the vehicle slows will be;
[tex]E_{battery}[/tex] = 50% × [tex]E_{kinetic}[/tex]
[tex]E_{battery}[/tex] = 50/100 × 809.379 kJ
[tex]E_{battery}[/tex] = 404.6895 kJ
Therefore, Electrical energy recovered in the battery is 404.6895 kJ
b)
For this electrical energy to be obtained from fuel, the chemical energy required will be;
[tex]E_{chemical}[/tex] = [tex]E_{battery}[/tex] / 25%
[tex]E_{chemical}[/tex] = 404.6895 kJ / 0.25
[tex]E_{chemical}[/tex] = 1618.758 kJ
Heat energy released per mass of ethanol combustion
(Lower heating value of ethanol) is 26.7kJ/g
Now, the mass of fuel needed to generate 1618.758 kJ will be;
[tex]m_{fuel}[/tex] = 1618.758 kJ / 26.7kJ/g
[tex]m_{fuel}[/tex] = 60.63 g
[tex]m_{fuel}[/tex] = 0.0606 kg
Therefore, Mass of fuel needed to store same amount of energy in the battery is 0.0606 kg
You drive on Interstate 10 from San Antonio to Houston, half the time at 75 km/h and the other half at 106 km/h. On the way back you travel half the distance at 75 km/h and the other half at 106 km/h. What is your average speed (a) from San Antonio to Houston, (b) from Houston back to San Antonio, and (c) for the entire trip
Answer:
Explanation:
a ) from San Antonio to Houston let distance be d km .
Average speed = total distance / total time
time = distance / speed
Total time = (d / 2 x 75 ) +( d / 2 x 106 )
= .0067 d + .0047 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
b ) from Houston back to San Antonio
Total time = (d / 2 x 106 ) +( d / 2 x 75 )
= .0047 d + .0067 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
c )
For entire trip :
total distance = 2d
total time = 2 x .0114 d
Average speed = 2 d / 2 x .0114 d
= 87.72 km /h .
When an object falls, its:
A. PE increases and KE decreases.
B. PE does not change.
C. PE and KE both increase.
D. PE decreases and kE increases
Answer:
Option D. is correct.
Explanation:
The object's mechanical energy refers to the sum of the potential and kinetic energies of the object. When an object falls, its potential energy (PE) decreases, and its kinetic energy (KE) increases. The increase in kinetic energy is exactly equal to the decrease in potential energy.
Option D. is correct.
A student drove to the university from her home and noted that the odometer reading of her car increased by 17.9 km. The trip took 26.6 min.
a) What was her average speed, in kilometers per hour?
b) IS she returned home by the same path 7 h 30 min after she left, what was her average speed and velocity for the entire trip?
Answer:
See calculation below
Explanation:
Average speed = Distance/Time
a) Given
Distance = 17.9km
Time = 26.6minutes
Time = 26.6/60 hr
Time = 0.443hr
Average speed = 17.9/0.443
Average speed = 40.38km/hr
b) If she returned home by the same path 7 h 30 min after she left, the distance will be the same;
Distance = 17.9km
Time = 7.5hr
Average speed = 17.9/7.5
Average speed = 2.387km/hr
Velocity of the entire trip = 40.38km/hr + 2.387km/hr
Velocity of the entire trip = 42.77km/hr
Hence the velocity of the entire trip is 42.77km/hr
The spectrum of a star shows a set of dark absorption lines equivalent to the absorption lines of the Sun but with one exception: Every line appears at a slightly longer wavelength, shifted toward the red end of the spectrum. What conclusion can be drawn from this observation
Answer:
The shift in the emission spectra of the relative velocity between the star and our planet, is called the relativistic doppler effect
Explanation:
The absorption and emission spectra are measured differently, the emission spectrum is the spectrum emitted by the star and the absorption spectrum is the absorption of these lines by the gases of our atmosphere, this absorption occurs for relatively broad Δλ.
The shift in the emission spectra of the relative velocity between the star and our planet, is called the relativistic doppler effect and has a red shift if the star moves away from us.
[tex]f_o = f_s \sqrt{\frac{1- v/c}{1 + v/c} }[/tex]
Two people are playing tug-of-war. Due to their choice of footwear, theircoefficient of static friction is different. Participant 1 has a mass of 60 kg, acoefficient of static friction of 2.0, and can pull with a maximum force of1000 N. Participant 2 has a mass of 80 kg and a coefficient of staticfriction of 1.2, and can pull with a maximum force of 1200 N. Who wins?
Answer:
Participant 1 wins
Explanation:
Coefficient of static, μ = F/N, where F is the frictional force and N is the normal force.
The force exerted by each participant is the sum of the frictional force acting on each of them and the maximum force with which each participant pulls on the rope.
Frictional force, F = μ * N
Normal force, N = mass * acceleration due to gravity, g
For Participant 1; μ = 2.0, mass = 60 kg, g = 9.8 m/s²
Frictional force = 2.0 * 60 * 9.8 = 1176 N
Total force = (1176 + 1000) = 2176 N
For Participant 2; μ = 1.2, mass = 80 kg, g = 9.8 m/s²
Frictional force = 1.2 * 80 * 9.8 = 940.8N
Total force = (940.8 + 1200) N = 2140.8 N
From the values obtained above, Participant 1 exerts more force than Participant 2, therefore, Participant 1 wins
A hovercraft is being driven across a lake on a very windy day. The wind exerts a force of 5000 N north on the hovercraft. The propellers driving the hovercraft also exert a force.
What is the net force (to 3.s.f ) on the hovercraft when the force applied to the hovercraft by the propellers is: 10 000 N west
Answer:
The net force on the hovercraft is 11200 N.
Explanation:
Given;
force exerted on the hovercraft by wind, F₁ = 5000 N north
force exerted on the hovercraft by the propeller, F₂ = 10,000 N west
The net force on the hovercraft is calculated as;
[tex]F_{net} = \sqrt{F_1^2 + F_2^2} \\\\F_{net} = \sqrt{5000^2 + 10,000^2} \\\\F_{net} = 11180.34 \ N\\\\F_{net} = 11200 \ N \ (3.s.f)[/tex]
Therefore, the net force on the hovercraft is 11200 N.
A 20.0 N force is necessary to stretch a spring 0.500 m. What is the spring constant of this spring?
The spring constant : k = 40 N/m
Further explanationGiven
Force = 20 N
The displacement of the spring=x=0.5 m
Required
The spring constant = k
Solution
Hooke's Law
F = k.x
k = F/x
Input the value :
k = 20/0.5
k = 40 N/m
Take 47 points. Hurry Someone save me just look the picture
Answer:
suppose buying pizza for a work party leads to positive morale and to the work being done in half the time. Pizza is the independent variable, Work speed is the dependent variable, The mediator, the middle man without which there would be no connection, is positive morale. Denaturation, in biology, the process of modifying the molecular structure of a protein. Denaturation involves the breaking of many of the weak linkages, or bonds (e.g., hydrogen bonds), within a protein molecule that is responsible for the highly ordered structure of the protein in its natural (native) state.
Explanation:
hope this helps have a good rest of your day :) ❤
Explanation:
HW1. For example, suppose buying pizza for a work party leads to positive morale and to the work being done in half the time. Pizza is the independent variable, Work speed is the dependent variable, The mediator, the middle man without which there would be no connection, is positive morale.
HW2. The word denature means to render food unpleasant or dangerous to consume, it is denatured by adding a substance known as a denaturant. Aversive agents—primarily bitterants and pungent agents—are used to produce an unpleasant flavor.
Hope It Helps U
Please Mark As Brainl
PLEASE PLEASE PLEASE HELP
Answer:
just use y = mx + b to create an equation of the line in the graph.
then you can plug in 15 for x and then convert 1.5 hours into minutes and plug it in as well.
you dont even need to make an equation for a line. just add 0.2 for every 3 mins.
at 9, it's 0.6, so at 12 it would be 0.8, and then 15 it would be 1.0.
go again all way for 1. 5 hours.
Explanation:
the slope is 0.1/1.5 so you equation would be y = 0.1/1.5x
the slope is rise/run.
Two stationary positive point charges, charge 1 of magnitude 3.95 nC and charge 2 of magnitude 1.80 nC, are separated by a distance of 39.0 cm. An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two charges.What is the speed of the electron when it is 10.0 cm from charge 1?
Answer:
the speed of the electron from charge q1 is 7.17×10⁶ m/s
Explanation:
Given the data in the question;
the potential at the center of the two charges will be;
V = k( q1/(d/2) + q2/(d/2)
so we substitute
V = (9×10⁹)( (3.95×10⁻⁹/(0.39/2) + 1.80×10⁻⁹/(0.39/2)
V = 265.4 V
the potential at a distance of 10 cm from the charges will be
V = k( q1/(d1) + q2/(d2)
(d1 = 10cm = 0.1m and d2 = 39cm - 10cm = 29cm = 0.29m )
V' = (9×10⁹)( (3.95×10⁻⁹/0.1 + 1.80×10⁻⁹/0.29
V' = 411.4 V
Now, from the conservation of energy the speed of the electron from charge q1 will be;
E = ( V' - V) qe
1/2mv² = ( V' - V) qe
v² = [( V' - V) qe] / 1/2m
v =√ ([( V' - V) qe] / 1/2m)
v =√ ([2( V' - V) qe] / m)
we substitute
v =√ (2[( 411.4 - 265.4) 1.6×10⁻¹⁹] / 9.1×10³¹)
v = 7.17×10⁶ m/s
Therefore, the speed of the electron from charge q1 is 7.17×10⁶ m/s
If vec A and vec B are vectors and vec B = -vec A , which of the following is true ?
a) The magnitude of is equal to the negative of the vec B magnitude of vec A
b) Ā and vec B are perpendicular .
c) The direction angle of is equal to the direction angle of vec B A plus 180 degrees
d ) vec A + vec B =2 vec A .
Answer:
If A + B = C for the vector equation then substituting for B gives
A + (-A) = C = 0
The only thing that can be said about "C" is that it has zero magnitude.
Basketball player Darrell Griffith is on record as
attaining a standing vertical jump of 1.2 m (4 ft).
(This means that he moved upward by 1.2 m after
his feet left the floor.) Griffith weighed 890 N (200
lb). g=9.8 m/s2
1- What is his speed as he leaves the floor?
2- if the time of the part of the jump before his feet left the floor was 0.300s, what was the magnitude of his average acceleration while he was pushing against the floor?
Explanation:
1.
We use the equation
h = [tex]\frac{gt^2}{2}[/tex], where
h is the height traveled,
g is the acceleration due to gravity and
t is the time taken to reach height h.
We can now calculate t to be
[tex]\sqrt{\frac{2*1.2 m}{9.81 m/s^2} }[/tex]
= 0.495 s
Let v be the initial velocity of the player.
The player deaccelarates from v m/s to 0 m/s in 0.495 s at the rate of 9.81 m/s^2.
v = 9.81 m/s^2 x 0.495 s = 4.85 m/s
2.
The player takes 0.3 s to increase his velocity from 0 m/s to 4.85 m/s. So his average accelaration is
4.85 m/s / 0.3 s = 16.2 m/s^2
The other name of eureka can
Answer:
I found it!
Explanation:
Answer:
Explanation:
displacement vessels
The can is filled to the top with water and the object placed in it. The volume of the object is equal to the volume of the water that is forced through the spout. Eureka cans are named after a scientist called Archimedes who first recorded this idea. They are sometimes also called displacement vessels.
Marlon is studying a crab population. He has a large batch of crabs that were captured in the ocean. He places a plastic tag on a leg of each crab and releases the entire batch back into the ocean. The tags
include a phone number that can be called it the crabs are caught. For each crab, Marion records the location he released the crab and the location that it was recaptured. What can Marion measure with
this data
А
the speed the crabs traveled
B
the velocity the crabs traveled
the acceleration of the crabs
D
the displacement of the crabs
A bird lands on a bird feeder which is connected to a spring. The mass of the bird is exactly the same as the mass of the bird feeder. How does the added mass affect the period of oscillation of the bird feeder?
Answer:
The added mass will mean a longer period of oscillation.
Explanation:
The period of oscillation here is given by the formula;
T = 2π√(m/k)
Where m is mass and k is spring constant
From the equation of oscillation period above, it's obvious that when we increase the mass, the oscillation period will also increase.
Thus, the added mass will mean a longer period of oscillation.
What is the total amount of kinetic and potential energy in a system ?
Answer:
Its the sum of the potential energy and the kinetic energy
Physical science-current can be increased by...
Option 3.) Increasing the voltage across the wire.
I know that the other answers are incorrect because, for one thing, the more resistance in a substance, the less flow of the current there is. Also, using a longer wire doesn't change anything, it just makes a electrical current go on longer. Lastly decreasing the voltage would make the current decrease in the atoms that flow through it to power an object.
-R3TR0 Z3R0
Which of the following statements are true?
a. By convention, the direction of a current is taken to be the direction of flow for negative charges.
b. When an electric field is applied to a conductor, the free electrons move only in the direction opposite the applied electric field.
c. Current is the total amount of charge that passes through a conductor's full cross section at any point per unit of time.
d. In order to maintain a steady flow of current in a conductor, a steady force must be maintained on the mobile charges.
e. In a circuit, current is delivered by the positive terminal of a battery, and it is used up by the time it returns to the negative terminal of the battery.
Answer:
A, C, D and E are the true statement about current flowing.
A(n) 17.4 g bullet is shot into a(n) 5506 g
wooden block standing on a frictionless sur-
face. The block, with the bullet in it, acquires
a speed of 1.61 m/s.
Calculate the speed of the bullet before
striking the block..
Answer in units of m/s.
The initial speed of the bullet = v₁= 511.07 m/s
Further explanationGiven
17.4 g bullet
5506 g wooden
The velocity of the block+bullet :1.61 m/s
Required
The initial speed
Solution
Momentum
m₁v₁+m₂v₂=m₁v₁'+m₂v₂'
v₂=0 ⇒block at rest
v₁'=v₂'=1.61 m/s
the equation becomes :
m₁v₁=(m₁+m₂)v'
17.4v₁=(17.4+5506)1.61
v₁= 511.07 m/s
I =p/4pir^2 solving for r
Answer: [tex]r = \sqrt{\frac{p}{4pil}}[/tex]
Explanation:
[tex]l = \frac{p}{4pir^2} \\4pir^2l=p\\r^2 = \frac{p}{4pil} \\r = \sqrt{\frac{p}{4pil}}[/tex]
5. (Liquids Gases) have particles with enough energy to spread out
throughoutcontainer. *
A)Liquids
B)Gases
Answer:
b gases
Explanation:
this is because gases spread out through out the entire container because they have no definite shape and are always moving.
A 45.0-kg girl stands on a 13.0-kg wagon holding two 18.0-kg weights. She throws the weights horizontally off the back of the wagon at a speed of 6.5 m/s relative to herself . Assuming that the wagon was at rest initially, what is the speed of the girl relative to the ground after she throws both weights at the same time
Answer:
v = 4.0 m/s
Explanation:
Assuming no external forces acting during the instant that the girl throws the weights, total momentum must be conserved.Since all the masses at rest initially, the initial momentum must be zero.So, due to momentum must keep constant, final momentum must be zero too, as follows:[tex]p_{f} = m_{w} * v_{w} + m_{g+w} *v_{g+w} = 0 (1)[/tex]
Assuming the direction towards the back of the wagon as positive, and replacing the masses in (1), we can solve for vg, as follows:[tex]v_{g+w} =- \frac{m_{w} *v_{w}}{m_{g+w} } = - \frac{36.0kg *6.5m/s}{58.0kg } = -4.0m/s (2)[/tex]
This means that the girl (along with the wagon on she is standing) will move at a speed of 4.0 m/s in an opposite direction to the one she threw the weights.During a phase change the temperature of a substance remains constant this is because during a phase heat changes the ____ energy of particles in a substance without changing their ____ energy
Answer:
Explanation:
individual and then net
hope that helps I could be wrong about this one though
Which type of wall would make the best soundproofing for room?
A.
1.0 centimeter thick glass
OB.
two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them
C.
two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them
OD.
1.0 centimeter thick steel
Among the options given, the choice that would make the best soundproofing for a room is option C: two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them.
Soundproofing is achieved by reducing the transmission of sound waves from one side of the wall to the other. In this case, the combination of two layers of glass with a vacuum between them helps to reduce sound transmission effectively.
Glass is a denser material compared to air or vacuum, so it naturally provides some sound insulation. Adding an extra layer of glass creates a barrier that helps to further dampen sound vibrations. The vacuum between the glass layers acts as an additional sound barrier, as sound waves have difficulty propagating through a vacuum due to the absence of a medium for transmission.
On the other hand, a single layer of 1.0 centimeter thick glass (option A) or two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them (option B) would provide some sound reduction but not as effective as the combination of glass layers with a vacuum in option C.
1.0 centimeter thick steel (option D) would have high density and mass, which could help with sound insulation to some extent. However, steel can still transmit vibrations and might not be as effective as the combination of glass layers with a vacuum in option C for soundproofing a room.
For more such questions on Soundproofing
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A 80 N force is needed to slide a 50.0 kg box across a flat surface at a constant velocity. What is the coefficient of kinetic friction between the box and the floor
Answer:
0.16
Explanation:
Given data
Force F= 80N
Mass m= 50kg
Reaction R= Weight= mg= 50*9.81= 490.5N
We know that
F=UR
Substitute and solve of U
U=F/R
U= 80/490.5
U=0.16
Hence the coefficient of friction is 0.16
___is found in fruits and honey. *
1.Maltose
2.Sucrose
3.Fructose
4.Galactose
Answer:
3. Fructose
Explanation:
Fructose is a sugar found naturally in fruits, fruit juices, some vegetables and honey.
it is number 3 (Fructose)
What type of change happens when the powder inside a firework is burned?
A.Freezing occurs from a chemical change.
B.Light is produced by a chemical change.
C.Rotting occurs from a chemical change.
D.Rust is produced by a chemical change.
Answer:
B light is produced by chemical change
Explanation:
im not the smartest but if you think about it, fireworks make bright lights. And what do they have: powders.
(but I still could wrong, sorry if I am)
4. Taylor Swift pushes Kanye West,
headfirst fearless, off a high dive with and
initial speed of 6m/s. If the platform is 20m
high, what is Kanye's impact velocity with
the water? (velocity and angle)
An ideal monatomic gas initially has a temperature of 300 K and a pressure of 5.79 atm. It is to expand from volume 420 cm3 to volume 1450 cm3. If the expansion is isothermal, what are (a) the final pressure and (b) the work done by the gas
Answer:
a) The final pressure is 1.68 atm.
b) The work done by the gas is 305.3 J.
Explanation:
a) The final pressure of an isothermal expansion is given by:
[tex] T = \frac{PV}{nR} [/tex]
[tex] T_{i} = T_{f} [/tex]
[tex] \frac{P_{i}V_{i}}{nR} = \frac{P_{f}V_{f}}{nR} [/tex]
Where:
[tex]P_{i}[/tex]: is the initial pressure = 5.79 atm
[tex]P_{f}[/tex]: is the final pressure =?
[tex]V_{i}[/tex]: is the initial volume = 420 cm³
[tex]V_{f}[/tex]: is the final volume = 1450 cm³
n: is the number of moles of the gas
R: is the gas constant
[tex] P_{f} = \frac{P_{i}V_{i}}{V_{f}} = \frac{5.79 atm*420 cm^{3}}{1450 cm^{3}} = 1.68 atm [/tex]
Hence, the final pressure is 1.68 atm.
b) The work done by the isothermal expansion is:
[tex] W = P_{i}V_{i}ln(\frac{V_{f}}{V_{i}}) = 5.79 atm*\frac{101325 Pa}{1 atm}*420 cm^{3}*\frac{1 m^{3}}{(100 cm)^{3}}ln(\frac{1450 cm^{3}}{420 cm^{3}}) = 305.3 J [/tex]
Therefore, the work done by the gas is 305.3 J.
I hope it helps you!
A spring with an unknown spring constant is hung vertically, and a 200 g (0.200 kg) mass is attached to the bottom. If the spring stretches 0.250 m from its resting position to the position at which the hanging mass is in equilibrium, what is the spring constant of this spring?
Answer:
k = 7.84 N/m
Explanation:
We are given;
Mass hanging object; m = 0.2 kg
Extension; Δx = 0.25 m
Now, formula for the force is;
F = k•Δx
Where k is the spring constant
Since we have mass, then F = W = mg = 0.2 × 9.8 = 1.96 N
Thus;
1.96 = k × 0.25
k = 1.96/0.25
k = 7.84 N/m