what is the efficiency of an engine that dies 288 J of work and exhausts 72 J of heat while taking 360 J of heat?
Answers
Answer:
80%
Explanation:
Energy Input: 360 J
Energy Output: 288 J
e= 288/360 × 100
e= 80%
Alternatively,
e= W(total)/ Q (in)
e= 288/360
e=0.8×100
e=80%
Related Questions
a trampoline launches a 50kg person 2m into the air. if the springs push with 1960N of force, how much displacement was there in the trampoline
Answers
Answer: 0.5 m
Explanation:
Given
Mass of the person is [tex]m=50\ kg[/tex]
Trampoline launches the person into the air up to height of [tex]h=2\ m[/tex]
Force experience by springs is [tex]F=1960\ N[/tex]
Here, the work done on displacing the springs is equivalent to the Potential energy acquired by the person i.e.
[tex]\Rightarrow F\cdot x=mgh\quad [\text{x=displacement of the trampoline}]\\\\\text{Insert the values}\\\\\Rightarrow x=\dfrac{50\times 9.8\times 2}{1960}\\\\\Rightarrow x=\dfrac{980}{1960}\\\\\Rightarrow x=0.5\ m[/tex]
Answer:
0.5
Explanation:
Select the correct answer. The motion of a car on a position-time graph is represented with a horizontal line. What does this indicate about the car’s motion? A. It’s not moving. B. It’s moving at a constant speed. C. It’s moving at a constant velocity. D. It’s speeding up.
Answers
If the car's motion appears as a horizontal line on a position-time graph, it shows that as time changes, the car's position doesn't change.
This is just a complicated way to say that the car is not moving. (A)
Answer: It's not moving.
Explanation:
I got it correct on edmentum.
It takes 130 j of work to compress a certain spring 0.10m. (a) what is the force constant of this spring? To compress the spring an additional 0.10m, does it take 130
Answers
Answer:
Explanation:
The PE equation for a mass/spring system is
[tex]PE=\frac{1}{2}k[/tex]Δx² and filling in:
[tex]130=\frac{1}{2}k(.10)^2[/tex] and
[tex]k=\frac{2(130)}{(.10)^2}[/tex] so
k = 26000 N/m
If the displacement from equilibrium changes more, the PE needed to compress it will also change.
[tex]PE=\frac{1}{2}(26000)(.20)^2[/tex] gives us that
PE = 520J
An object is moving with an initial velocity of 9 m/s. It accelerates at a rate of 1.5 m/s2
over a time of 20 s. What is its new velocity?
Answers
Answer:
39 m/s²
Explanation:
initial Velocity (u) = 9m/s
acceleration (a) = 1.5m/s²
time(t) = 20s
V=u + at
V=9 + 1.5(20)
V=9 + 30
V=39m/s
Physicist Max Planck showed how objects like stars give off different colors based on their temperature. What color are the hottest stars
Answers
Answer:
the brightest found are Blue - White with
Explanation:
The energy emission of objects increases with their temperature, specifically Wien described the process in an expression
[tex]\lambda_{maximum}[/tex] T = 2,898 10⁻³
With this expression we can find the temperature of the stars by the color they emit.
Specifically the Sun has a color of 550 nm which corresponds to 5400K
bright stars have a BLUE color corresponding to 7500K
the brightest found are Blue - White with a temperature of 20000K
A pair of forces with equal magnitude, opposite directions, and different lines of action is called a "couple." When a couple acts on a rigid object, the couple produces a torque that does not depend on the location of the axis. The drawing shows a couple acting on a tire wrench, each force being perpendicular to the wrench. Determine an expression for the torque produced by the couple when the axis is perpendicular to the tire and passes through the following. Express your answers in terms of the magnitude F of the force and the length L of the wrench.
Answers
The drawing shows the couple acting on a tire wrench is missing and so i have attached it.
We are to find an expression for the torque when the axis is perpendicular to the tire and passes through the points A, B & C
Answer:
Point A: τ = Fl
Point B: τ = 0
Point C: - Fl
Explanation:
Formula for torque is;
τ = F × d
Where;
F is perpendicular force
d is distance.
Thus;
> At point A, it means we are taking torque about point A and so we have;
τ = (-F × 0) + (F × L)
τ = Fl
> At point B, it means we are taking torque about point B and so we have;
τ = (-F × L/2) + (F × L/2)
τ = -(FL/2) + (FL/2)
τ = 0
> At point C, it means we are taking torque about point C and so we have;
τ = (-F × L) + (F × 0)
τ = -FL
What is this?
Picture
Answers
Answer:
may be upside down alphabet :"T"
Explanation:
A spherical cell has a radius of 2.3 μm , and the phospholipid bilayer that constitutes its membrane has a thickness of 3.75 nm . At its normal resting state, the outer membrane is at a voltage of 0V, and the inner membrane is at a voltage of -70mV. The dielectric constant of the cell membrane is roughly 9.0. What is the capacitance of the cell? (Note: the surface area of a sphere is 4πr2)
Answers
Answer:
Explanation:
The cell is acting like a shell .
Capacity of a shell is given by the following expression.
C= 4πk ε₀ x ab / (b-a )
k is dielectric constant , b and a are outer and inner radius ε₀ is a constant .
Here a = 2.3 x 10⁻⁶ m
b = 2.3 x 10⁻⁶ + .00375 x 10⁻⁶
= 2.30375 x 10⁻⁶ m
b -a = 3.75 x 10⁻⁹ m .
k = 9
4π ε₀ = 1 / 9 x 10⁹ = .111 x 10⁻⁹
C= .111 x 10⁻⁹ x 9 x 2.3 x 10⁻⁶ x 2.30375 x 10⁻⁶ / 3.75 x 10⁻⁹
= 1.41 x 10⁻¹² F
= 1.41 pF .
A car at a position 150 km [W] of Toronto travels to a position 400 km [W] of
Toronto. The total displacement of the car is:
Answers
Answer:
The total displacement of the car is 250 km.
Explanation:
Given that,
A car at a position 150 km [W] of Toronto travels to a position 400 km [W] of Toronto.
Total displacement = final position - initial position
= 400 km - 150 km
= 250 km
So, the total displacement of the car is 250 km.
The four laws of liquid pressure
Answers
Answer:
1-The liquid pressure is same at all points lying on the same horizontal plane in a stationary liquid.
2-The liquid pressure at a point inside the liquid is same in all directions.
3-The liquid pressure at a point inside the liquid is directly proportional to the depth of that point from the free surface of liquid.
4-The pressure of liquid at same depth is different for different liquids. It is directly proportional to density of liquid. That is, for same depth the liquid pressure is larger for liquid of larger density.
Explanation:
How do the rocks in the mantle move?
A. They do not move.
B. They move in convection currents.
C. They flow like water.
D. They move on top of the crust.
Answers
Answer:
b. they move in convection currents.
Explanation:
i learned this in 4th grade
A piano string of density 0.0050 kg/m is under a tension of 1,350 N. Find the velocity with which a wave travels on the string.
Answers
Answer:
519.62 m/s
Explanation:
Applying,
v = √(T/m').............. Equation 1
Where v = velocity of the wave, T = Tension on the string, m' = mass per unit length of the string
From the question,
Given: T = 1350 N, m' = 0.005 kg/m
Substitute these values into equation 1
v = √(1350/0.005)
v = √(270000)
v = 519.62 m/s
The reservoir stores 6 500 000 m3 of water. The density of the water is 998 kg/m3. Calculate the mass of water in the reservoir. Give your answer in standard form.
Answers
Answer:
Mass = 64,870,000,000 kilograms
Explanation:
Given the following data;
Density = 998 kg/m³
Volume = 6,500,000 m³
To find the mass of water in the reservoir;
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 equation;
Density = mass/volume
Making mass the subject of formula, we have;
Mass = density * volume
Mass = 998 * 6,500,000
Mass = 64,870,000,000 kilograms
In the diagram, q1 = +2.00 x 10-5 C,
q2 = +3.80 x 10-6 C, and q3 = +5.30 x 10-5 C.
What is the electric potential energy, Ue, for
charge qy? Include the correct sign (+ or -).
Answers
Answer:
U = 3.59 10⁻⁹ J
Explanation:
Electric potential energy is
U = k ∑ [tex]\frac{q_iq_j }{r_i_j}[/tex]
in this case
U = k (q₁q₂ / r₁₂ + q₁q₃ / r₁₃ + q₂q₃ / r₂₃)
the distances are
r₁₂ = 1.15
r₁₃ = 1.15 +2.88 = 4.03 m
r₂₃23 = 2.88
we substitute
U = 9 109 (2 10-5 3.8 10-6 / 1.15 + 2 10-5 5.30 10-5 / 4.03 + 3.8010-6 53 010-5 / 2.88)
U = 9 109 (6.609 10-11 + 2.63 10-10 + 6.99 10-11)
U = 9 109 (39,899 10-11)
U = 3.59 10⁻⁹ J
Answer:
Q2 = 0.0346 J
Explanation:
I don't know what Q1 is but I did solve for Q2. I'm using this because no other question has been asked to solve for Q2 :)
A 25.0kg girl pushes a 50.0kg boy with a force of 100.0N. What is the acceleration of the girl?
Answers
Answer:
im pretty sure it should be 50.0
TRUE OR FALSE. if an object covers equal distance at equal intervals of time, then it is moving at constant speed and not accelerating
Answers
Answer:
True
Explanation:
Speed = distance/time
If distance and time are the same, then the right hand side of the equation remains the same, causing us to solve the left to the same value
As the distance is the same (say 50m) and the time is the same (say 50s) then the speed must be the same (1m/s)
What is the enthalpy change, AH, for this reaction? Show your work to receive full credit. URGENT PICTURE INCLUDED !!!
Answers
Answer:
150 kJ
Explanation:
Applying,
ΔH = Energy level of Product(E') - Energy level of reactant(E)
Where ΔH = enthalpy change, E' and E = energy level of the product and the reactant respectively
ΔH = E'-E............. Equation 1
From the diagram,
Given: E' = 200 kJ, E = 50 kJ
Substitute these values into equation 1
ΔH = 200-50
ΔH = 150 kJ
Hence the enthalpy change for the reaction is 150 kJ
A satellite of mass 5460 kg orbits the Earth and has a period of 6520 s
A)Determine the radius of its circular orbit.
B)Determine the magnitude of the Earth's gravitational force on the satellite.
C)Determine the altitude of the satellite.
Answers
Answer:
what if I do and b then someone else c I don't have enough time pls
A delivery boy on a bicycle drags a wagon full of newspapers by pedaling at 0.90 m/s for 45 minutes using a force of 40 N. How much work has the boy done?
Answers
Answer:
Explanation:
The equation for work is
W = FΔx
We are looking for work, so that means we have to be able to fill in the Force and the displacement. We have Force, but we don't have displacement. But the thing we need to do first is change the 45 minutes to seconds because the velocity is in m/s, not m/min.
45 minutes is 2700 seconds.
That means that the displacement is
Δx = (.90)(2700) so
Δx = 2430 m
Now we plug that in to find work, along with the given Force:
W = 40(2430) so
W = 97200 J (and that is not the correct number of sig fig's but I have a feeling you're not too into that in class, because if you were, the 40 N would be expressed as 40.0 or 4.0 × 10¹)
An amoeba has 1.00 x 1016 protons and a net charge of 0.300 pC. Assuming there are 1.88 x 106 fewer electrons than protons, If you paired them up, what fraction of the protons would have no electrons
Answers
Answer:
The fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]
Explanation:
We are given that
Amoeba has total number of protons=[tex]1.00\times 10^{16}[/tex]
Net charge, Q=0.300pC
Electrons are fewer than protons=[tex]1.88\times 10^6[/tex]
We have to find the fraction of protons would have no electrons.
The fraction of the protons would have no electrons
=[tex]\frac{Fewer\;electrons}{Total\;protons}[/tex]
The fraction of the protons would have no electrons
=[tex]\frac{1.88\times 10^{6}}{1.00\times 10^{16}}[/tex]
[tex]=1.88\times 10^{-10}[/tex]
Hence, the fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]
Hallar la distancia que recorre una movil al cabo
de 8s si posee una velocidad de 5m/s y acelera a razón de 3 m/s
Answers
Answer:
Distancia, S = 136 metros
Explanation:
Dados los siguientes datos;
Aceleración, a = 3 m/s²
Velocidad inicial, u = 5 m/s
Tiempo, t = 8 segundos
Para encontrar la distancia recorrida, usaríamos la segunda ecuación de movimiento;
S = ut + ½at² Sustituyendo en la fórmula, tenemos;
S = 5 × 8 + ½ × 3 × 8²
S = 40 + 1,5 × 64
S = 40 + 96
Distancia, S = 136 metros
Naomi Osaka, a Japanese-African-American tennis player is the 2021 Australian Open Champion, and the first Asian tennis player in Women's Tennis Association (WTA) history to be ranked first in Singles. To celebrate her win, Naomi Osaka hits a ball into the stands at 40. m/s and at an angle 30.° above the horizontal. On its way down, the ball is caught by a spectator 12 m above the point where the ball was hit.
a) Calculate the time it takes the tennis ball to reach the spectator.
b) Calculate the ball's horizontal range (horizontal distance travelled).
Answers
Answer:
(a) t = 0.75 s
(b) d = 26 m
Explanation:
Height, h = 12 m
Angle, A = 30 degree
initial velocity, u = 40 m/s
(a) Let the time is t.
Use second equation of motion
[tex]h = u t + 0.5 at^2\\\\12 = 40 sin 30 t - 0.5 \times10 \times t^2\\\\12 = 20 t - 5 t^2\\\\5 t^2 - 20 t + 12 =0 \\\\t = \frac{20\pm \sqrt{400-240}}{10}\\\\t = \frac{20\pm 12.65}{10}\\\\t = 3.3 s, 0.75 s[/tex]
(b) d = u cos A t
d = 40 x cos 30 x 0.75 = 26 m
explain what characterises a sound as noise or music
Answers
Explanation:
Noise is sound with a continuous structure. Music is composed of sounds with a fundamental frequency and overtones. Noise is composed of sounds with frequencies that range continuously in value from as low as you can hear to as high as you can hear — not necessarily at equal intensity, however.
What is the direction of the magnetic field due to the positive charge at the location of the negative charge
Answers
Answer:
A positively charged object moving due west in a region where the Earth's magnetic field is due north experiences a force that is straight down as shown.
A negative charge moving in the same direction would feel a force straight up.
[tex]what \: is \: reflection \: of \: light \: \: \: \: {?}[/tex]
Answers
What is displacement?
An objects overall change in position
The total measure of how far one travels
a change in direction
Answers
Answer:
An object overall change in position
Explanation:
ans maybe corre6
Why Newton's law of gravitation also called universal law?
Answers
Answer:
Explanation:
Newton's law of gravitation states that every particle of matter attracts any other particle in the universe with a force directly proportional to the product of there masses and inversely proportional to the square of the distance between them.
This law is also called universal law because it is applicable to all masses at all distances irrespective of the medium.
A bicycle and a car start their journey at the same time the cyclist reaches it's top speed of 10mls in 15 the car reaches a speed if 15 MLS in55 which has the greater acceleration the car or the bicycle
Answers
Complete question is;
A bicycle and a car start their journey at the same time the cyclist reaches it's top speed of 10m/s in 15 s, the car reaches a speed of 15 m/s in 55 s. which has the greater acceleration the car or the bicycle.
Answer:
The bicycle has the greater acceleration.
Explanation:
Cyclist reaches a top speed of 10m/s in 15 s.
Formula for acceleration here is;
a = v/t
a = 10/15
a = 0.67 m/s²
Car reaches a speed of 15 m/s in 55 s.
Thus;
a = 15/55
a = 0.27 m/s²
From the 2 acceleration values gotten, we can say that;
The bicycle has the greater acceleration.
A car moves with the speed of 40 km/hr for the first half and 60 km/hr
for Second half distance "What is the average distance of cars.
Answers
Answer:
50 km/h
Explanation:
[tex](40 + 60) / 2[/tex]
-> [tex]50[/tex] (km/h)
Answer the question plz
Answers
Answer:
b and d
Explanation:
