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2 years ago

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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Part b)

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Part c)

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Part d)

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Part e)

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Explanation:

Part a)

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Part b)

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Part c)

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$\alpha = \frac{\omega_f - \omega_i}{t}$

$\alpha = \frac{8.17 - 0}{11.9}$

$\alpha = 0.69 rad/s^2$

Part d)

When its angular speed changes to 120 rpm

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$\omega_2 = 2\pi (\frac{120}{60})$

$\omega_2 = 12.56 rad/s$

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$\omega_f^2 - \omega_i^2 = 2 \alpha \theta$

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Part e)

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$\omega_f - \omega_i = \alpha t$

$12.56 - 8.17 = 0.48 t$

$t = 9.14 s$

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Cindy exerts a force of 40 newtons and moves a chair 6 meters. Her brother Andy pushes a different chair for 6 meters while exer

sesenic [268]

Work formula:
W = F * d
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F 2 = 30 N; d 2 = 6 m.
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W ( Andy ) = 30 * 6 = 180 Nm
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hope it helps!

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Paladinen [302]

Answer:

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