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2 years ago

Which best describes how combustion works?

Physics

2 answers:

miv72 [106K]2 years ago

6 0

Answer: A) It breaks and forms bonds of fuel to release thermal energy.

Explanation:

Chemical energy is the energy stored in the bonds of molecules.

Thermal energy is the energy possessed by a body by virtue of its temperature.

Combustion is a chemical reaction in which a fuel is burnt in the presence of oxygen to form carbon dioxide, water and heat.

$C_xH_y+x+\frac{y}{4}O_2\rightarrow xCO_2+\frac{y}{2}H_2O+Energy$

Thus the chemical energy stored in the bonds of reactants is converted to thermal energy and heat is released in the combustion reaction.

jekas [21]2 years ago

3 0

The answer is A, it breaks down and releases thermal energy.

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An electron has an initial velocity of (19.0 j + 18.0 k) km/s and a constant acceleration of (3.00 ✕ 1012 m/s2)i in a region in

asambeis [7]

Answer:

$E=(-17.08 i +7.2 j -7.6 k )N/C$

Explanation:

$v= (19.0j+18.k)km/s$

$a=3.0x10^{13}m/s^2$

$\beta= 400x10{-6}T$

Electron information needed to solve the question:

$m_e=9.11x10^{-31}kg$

$q=-1.6x10{-19}C$

$F=F_E+F_B=q*(E+Vx \beta)$

$F=m*a$

$m*a=q*(E+Vx\beta)$

$E=\frac{m*a}{q}-(Vx\beta )$

$E=\frac{9.11x10{-31}kg*3.0x10^{12}m/s^2}{-1.6x10{-19}C}-[(19.0x10^3mj+18.0x10^3m)xi(400x10^{-6}T)]$

$E=-i17.08N/C-[7.6(-k)+7.2(j)]N/C$

$E=(-17.08 i +7.2 j -7.6 k )N/C$

6 0

2 years ago

A car accelerates from rest at -3.00m/s^2. What is the velocity at the end of 5.0s? What is the displacement after5.0s?

Andrew [12]

Speed = (acceleration) x (time)
Velocity = (speed) in (direction of the speed)

Speed = (-3 m/s²) x (5 s) = 15 m/s
Velocity =
   (15 m/s) in the direction opposite to the direction you call positive.

Displacement = (distance between start-point and end-point)
   in the direction from start-point to end-point.

Distance = (1/2) (acceleration) (time)²
Distance = (1/2) (3 m/s²) (5 s)²
   = (1/2) (3 m/s²) (25 s²) = 37.5 meters

Displacement =
   37.5 meters in the direction opposite to the direction you call positive.

5 0

2 years ago

I would love to stretch a wire from our house to the Shop so I can 'call' my husband in for meals. The wire could be tightened t

dezoksy [38]

Note: I'm not sure what do you mean by "weight 0.05 kg/L". I assume it means the mass per unit of length, so it should be "0.05 kg/m".

Solution:
The fundamental frequency in a standing wave is given by
$f= \frac{1}{2L} \sqrt{ \frac{T}{m/L} }$
where L is the length of the string, T the tension and m its mass. If we plug the data of the problem into the equation, we find
$f= \frac{1}{2 \cdot 24 m} \sqrt{ \frac{240 N}{0.05 kg/m} }=1.44 Hz$

The wavelength of the standing wave is instead twice the length of the string:
$\lambda=2 L= 2 \cdot 24 m=48 m$

So the speed of the wave is
$v=\lambda f = (48 m)(1.44 Hz)=69.1 m/s$

And the time the pulse takes to reach the shop is the distance covered divided by the speed:
$t= \frac{L}{v}= \frac{24 m}{69.1 m/s}=0.35 s$

7 0

3 years ago

Need help ASAPJenna made an electric circuit as seen in the picture. She placed a thermometer near her light bulb. After the lig

zepelin [54]

B) The temperature in the thermometer went up.

7 0

3 years ago

Read 2 more answers

Explain why nuclear fission and nuclear fusion release large amounts of energy

levacccp [35]

Answer:

Because of the formula $E=mc^2$

Explanation:

In this problem we are describing two different processes:

Nuclear fission occurs when a heavy, unstable nucleus breaks apart into two or more lighter nuclei

Nuclear fusion occurs when two (or more) light nuclei fuse together producing a heavier nucleus

In both cases, the total mass of the final products is smaller than the total mass of the initial nuclei.

According to Einsten's formula, this mass difference has been converted into energy, as follows:

$E=\Delta mc^2$

where:

E is the energy released in the reaction

$\Delta m$ is the mass defect, the difference between the final total mass and the initial total mass

$c=3.0 \cdot 10^8 m/s$ is the speed of light

From the formula, we see that the factor $c^2$ is a very large number, therefore even if the mass defect $\Delta m$ is very small, nuclear fusion and nuclear fission release huge amounts of energy.

8 0

2 years ago