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Nat2105 [25]
2 years ago
8

A machine has an efficiency of 20 percent. Find the input work if the output work is 140 Joules

Physics
2 answers:
Lapatulllka [165]2 years ago
6 0

Answer:

X= 700 Joules

Explanation:

The question asked about the efficiency of the work done.

The formula for efficiency is: Efficiency = (Useful output / input work) * 100%

The useful output given in the question is 140J, the question asked for input work. Let X be the input work. It is also given that the efficiency is 20%.

Using the formula of efficiency,

20 = (140/X) * 100

So, we simply solve the above equation.

X= 140*100/20

X= 700 Joules

vazorg [7]2 years ago
4 0

Answer:

The input work = 700 Joules

Explanation:

Given Data:

Efficiency = 20%

Output work = 140 joules

Input work = ?

The input work done can be calculated using the efficiency formula;

Efficiency = output work done/input work done * 100

Substituting, we have

20 = 140/Input work * 100

20 = 14000/input work

20*input work = 14000

input work = 14000/20

               = 700 joules

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Answer:

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Check attachment for the given diagram

Explanation:

Given that,

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Since it comes to rest, then, the final velocity is 0m/s

v=3m/s

Using equation of motion to calculate the linear acceleration or tangential acceleration

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0=9+12a

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a=-0.75m/s²

The negative sign shows that the cylinder is decelerating.

Then, a=0.75m/s²

So, using the relationship between linear acceleration and angular acceleration.

a=αr

Where

a is linear acceleration

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α=a/r

From the diagram r=250mm=0.25m

Then,

α=0.75/0.25

α =3rad/sec²

The angular acceleration is =3rad/s²

b. Time take to come to rest

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v=u+at

0=3-0.75t

0.75t=3

Then, t=3/0.75

t=4 secs

The time take to come to rest is 4s

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2 years ago
An electric motor consumes 9.00 kj of electrical energy in 1.00 min. if one-third of this energy goes into heat and other forms
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A helium ion of mass 4m and charge 2e is accelerated from rest through a potential difference V in vacuum. Its final speed will
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8 0
1 year ago
A friend of yours who has not taken an astronomy class looks at your textbook and really likes the picture of the Pleiades, a cl
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Answer:

<em>C. the blue colour of the Earth's sky</em>

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8 0
2 years ago
Una cuerda de violin vibra con una frecuencia fundamental de 435 Hz. Cual sera su frecuencia de vibracion si se le somete a una
EleoNora [17]

Answer:

a)  f = 615.2 Hz      b)  f = 307.6 Hz

Explanation:

The speed in a wave on a string is

         v = √ T / μ

also the speed a wave must meet the relationship

          v = λ f

           

Let's use these expressions in our problem, for the initial conditions

            v = √ T₀ /μ

             √ (T₀/ μ) = λ₀ f₀

now it indicates that the tension is doubled

         T = 2T₀

          √ (T /μ) = λ f

          √( 2To /μ) = λ f

         √2  √ T₀ /μ = λ f

we substitute

         √2 (λ₀ f₀) = λ f

if we suppose that in both cases the string is in the same fundamental harmonic, this means that the wavelength only depends on the length of the string, which does not change

           λ₀ = λ

           f = f₀ √2

           f = 435 √ 2

           f = 615.2 Hz

b) The tension is cut in half

         T = T₀ / 2

         √ (T₀ / 2muy) =  f = λ f

          √ (T₀ / μ)  1 /√2 = λ f

           fo / √2 = f

           f = 435 / √2

           f = 307.6 Hz

Traslate

La velocidad en una onda en una cuerda es

         v = √ T/μ

ademas la velocidad una onda debe cumplir la relación

          v= λ f  

           

Usemos estas expresión en nuestro problema, para las condiciones iniciales

            v= √ To/μ

             √ ( T₀/μ) = λ₀ f₀

ahora nos indica que la tensión se duplica

         T = 2T₀

          √ ( T/μ) = λf

          √ ) 2T₀/μ = λ f

         √ 2 √ T₀/μ = λ f

         

substituimos  

         √2    ( λ₀ f₀)  =  λ f

si suponemos que en los dos caso la cuerda este en el mismo armónico fundamental, esto es que la longitud de onda unicamente depende de la longitud de la cuerda, la cual no cambia

                 λ₀ =  λ

           f = f₀ √2

           f = 435 √2

           f = 615,2 Hz

b)  La tension se reduce a la mitad

         T = T₀/2    

         RA ( T₀/2μ)  =  λ  f

          Ra(T₀/μ) 1/ra 2  =  λ f

           fo /√ 2 = f

           f = 435/√2

           f = 307,6 Hz

5 0
2 years ago
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