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2 years ago

13

You have designed a machine that requires 1000 J of work from a motor for every 800 J of useful work done by the machine. What i

s the efficiency of the machine?

1 answer:

valentinak56 [21]2 years ago

4 0

Answer:

80%

Explanation:

$efficiency = \frac{useful \: work \: done}{total \: energy \: input}$

800 / 1000 = 0.8

Efficiency = 0.8 *100 = 80%

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5. Describe the properties of each of these parts of the Earth’s interior: lithosphere, mantle, and core. What are they made of?

Arisa [49]

Hey there!

Okay so, the Lithosphere is made out of Earth’s outermost layer, which is composed of rocks in the crust and the upper mantle that behave as brittle solids.

The Mantle is made up of rock containing silicon, iron, magnesium, aluminum, oxygen and other minerals.

The Core has two parts. The solid inner core made up of iron. The outer core is surrounded by a liquid composed of a nickel-iron alloy.

I hope this helps!

8 0

4 years ago

lasers 1 and 2 emit light of the same color, and the electric field in the beam of laser 1 is twice as strong as the e-field of

bonufazy [111]

Answer:

The intensity of laser 2 is 4 times of the intensity of laser 1.

Explanation:

The intensity in terms of electric field is given by :

$U=\dfrac{1}{2}\epsilon_o E^2$

E is electric field

It means, $U\propto E^2$

In this problem, lasers 1 and 2 emit light of the same color, and the electric field in the beam of laser 1 is twice as strong as the e-field of laser 2.

Let E is electric field in the beam of laser 1 and E' is the electric field in the beam of laser 2. So,

$\dfrac{U}{U'}=(\dfrac{E}{E'})^2$

We have,

E'=2E

So,

$\dfrac{U}{U'}=\dfrac{E^2}{(2E)^2}\\\\\dfrac{U}{U'}=\dfrac{E^2}{4E^2}\\\\\dfrac{U}{U'}=\dfrac{1}{4}\\\\U'=4\times U$

So, the intensity of laser 2 is 4 times of the intensity of laser 1.

6 0

3 years ago

Aluminium,metal,glass,and paper:

Travka [436]

Aluminum metal is a good example of conductor of electricity while glass and paper are good example of insulators.

<h3>What is a conductor?</h3>

A conductor is material that allows easy passage of electric current through the.

<h3>Examples of conductors</h3>

All metals are good examples conductors. such as aluminum, iron, silver, etc.

<h3>What is a non conductor?</h3>

A non conductor or insulator is a material which does not allow easy passage of electric current through them.

<h3>Examples of insulators</h3>

glass
paper
wood, etc

Thus, aluminum metal is a good example of conductor of electricity while glass and paper are good example of insulators.

The complete question is below:

aluminium,metal,glass,and paper, are examples of what?

Learn more about conductors here: brainly.com/question/24154868

#SPJ1

7 0

2 years ago

Use the following photoelectric graph to answer the following question:

8090 [49]

Answer:

2.9 E14 Hz

Explanation:

As we know by Einstein's equation that energy incident on the photo sensitive surface will be used by the surface to eject electron out of the surface with some kinetic energy.

This is given by

$E = \phi + KE$

now the threshold frequency is the minimum frequency of the incident photons due to which electrons are ejected out with minimum kinetic energy or least kinetic energy.

So here when KE = 0 in the graph then corresponding to that position the frequency will be given as threshold frequency

so here from graph when KE = 0

$f = 2.9 E14 Hz$

8 0

4 years ago

WHICH TYPES OF ENERGY ARE HAPPENING

Lady bird [3.3K]

Answer:

mecanichal energy

Explanation:

................

8 0

4 years ago