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3 years ago

14

A machine is supplied energy at a rate of 4,000 W and does useful work at a rate of 3,760 W. What is the efficiency of the machi

ne?

2 answers:

Gemiola [76]3 years ago

5 0

Efficiency = (output power) / (input power)

= (3,760 joule/sec) / (4,000 joule/sec)

= 3,760 / 4,000 = 0.94 = 94%

777dan777 [17]3 years ago

5 0

your answer is 94 percent

i just took the test

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3 years ago

a motorcycle starts from rest covers 200 meter distance in 6 second calculate final velocity and acceleration

Ivanshal [37]

Explanation:

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2 years ago

A police car is driving down the street with it's siren on. You are standing still on the sidewalk beside the street. If the fre

AleksandrR [38]

Answer:

A) 1568.60 Hz

B) 1437.15 Hz

Explanation:

This change is frequency happens due to doppler effect

The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source

$f_(observed)=\frac{(c+-V_r)}{(C+-V_s)} *f_(emmited)\\$

where

C = the propagation speed of waves in the medium;

Vr= is the speed of the receiver relative to the medium,(added to C, if the receiver is moving towards the source, subtracted if the receiver is moving away from the source;

Vs= the speed of the source relative to the medium, added to C, if the source is moving away from the receiver, subtracted if the source is moving towards the receiver.

A) Here the Source is moving towards the receiver(C-Vs)

and the receiver is standing still (Vr=0) therefore the observed frequency should get higher

$f_(observed)=\frac{C}{C-V_s} *f_(emmited)\\=\frac{343}{343-15}*1500\\ =1568.60 Hz$

B)Here the Source is moving away the receiver(C+Vs)

and the receiver is still not moving (Vr=0) therefore the observed frequency should be lesser

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3 0

3 years ago

Microwaves have a higher frequency than radio waves, so why is it that they don't travel faster?

Lubov Fominskaja [6]

Answer: Energy requirement or consumption also increases as frequency goes higher. Hence, those low-frequency to mid-frequency waves are commonly referred to as radio waves and essentially, they have longer wavelengths. On the other hand, microwaves have higher frequencies and shorter wavelengths.

Explanation: therefore that's why they don't travel faster.

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2 years ago

The gravitational force between two objects (mass1 = 10kg, mass2 = 6kg) is measured when the objects are 12 centimeters apart. I

Yanka [14]

Since the new distance is 3 times the old distance,
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8 0

3 years ago