All categories

2 years ago

Can anyone please explain this point with an example. I have presentation tomorrow.

Physics

1 answer:

r-ruslan [8.4K]2 years ago

8 0

Explanation:

Efficiency is a way of describing the amount of useful output a process or machine can generate as a percentage of the input required to make it go. In other words, it compares how much energy is used to do work versus how much is lost or wasted to the environment. The more efficient the machine, the less energy wasted.

For example, if a heat engine is able to turn 75 percent of the fuel it receives into motion, while 25 percent is lost as heat in the process, it would be 75 percent efficient. Out of the original 100 percent of the fuel, 75 percent was output as useful work.

the equation:

energy efficiency =useful output energy/total input energy

You might be interested in

Two identical conducting small spheres are placed with their centers 0.290 m apart. One is given a charge of 12.0 nC and the oth

Solnce55 [7]

Answer:

Force between two identical conducting ball will be $2.65\times 10^{-5}N$

Explanation:

We have given there is two identical conducting small spheres having charge $q_1=12nC=12\times 10^{-9}C$ and $q_2=-21nC=-21\times 10^{-9}C$

Distance between centers of the ball is 0.290 m

So r = 0.290 m

We have to fond the electric force between the balls

According to Coulomb's law force between two charges is given by

$F=\frac{1}{4\pi \epsilon _0}\frac{q_1_2}{r^2}=\frac{Kq_1q_2}{r^2}$

So force $F=\frac{9\times 10^{9}\times 12\times 10^{-9}\times 21\times 10^{-9}}{0.293^2}=2.65\times 10^{-5}N$

So force between two identical conducting ball will be $2.65\times 10^{-5}N$

4 0

3 years ago

For Al, its atomic number is 13 and its mass number is 27. How many neutrons does it have? A. 13 B. 14 C. 26 D. 27 E. 40

sveta [45]

Answer:

B. 14

Explanation:

For an element:

- Atomic number: is the number of protons in the nucleus (p)

- Mass number: it is the number of protons (p) + neutrons (n) in the nucleus

For Al (aluminium), we have:

p = 13

p + n = 27

Substituting the first equation into the second one, we find the number of neutrons:

n = 27 - p = 27 - 13 = 14

5 0

4 years ago

Helpp! If the box moves 12m to the right calculate the work done on the box.

Murrr4er [49]

Answer:

80 times 12=960

Explanation:

You have to do the equation for work, the equation is work= force times distance, the force here is 80newtons, the distance is 12meters, so you would do 80 times 12 to get your answer of 960

8 0

3 years ago

Explain how are position time, velocity, and acceleration related to each other?

pogonyaev

I had this question before I think was it A or B.

6 0

3 years ago

The temperature of a heat engine is 500 K. Some of the heat generated by the engine flows to the surroundings, which are

Naddik [55]

Answer:

The efficiency of the engine is 75% under given conditions.

Explanation:

Efficiency is defined as the ratio of work done by the engine to the total heat supplied to a heat engine. We know work done by the heat engine be difference between total heat supplied $\left(Q_{h}\right)$ by total heat utilized $\left(Q_{c}\right)$ . We can derive formula for efficiency by considering the above factors, $\text { efficiency }=\frac{\text { work done }}{\text { heat suplied }}=\frac{Q_{h}-Q_{c}}{Q_{h}}=1-\frac{Q_{c}}{Q_{h}}=1-\frac{T_{1}}{T_{2}} \therefore \text { efficiency }=1-\frac{T_{1}}{T_{2}}$

Now consider a heat engine is at a temperature of 500K and the heat produced by the engine released to the surroundings at a temperature of 125K. The efficiency is calculated by using the above formula, $\text { efficiency }=1-\frac{T_{1}}{T_{2}}=1-\frac{125}{500}=1-0.25=0.75$

∴ Efficiency of the engine is 75%

8 0

3 years ago