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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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What is the average power consumption in watts of an appliance that uses 5.00 kWh of energy per day? How many joules of energy d

denpristay [2]

Answer:

(A) power = 0.208 kW = 208 watts

(B) energy = 6.6 x 10^{9} joules

Explanation:

energy consumed per day = 5 kWh

(a) find the power consumed in a day

1 day = 24 hours

power = \frac{energy}{time}

power = \frac{5}{24}

power = 0.208 kW = 208 watts

(b) find the energy consumed in a year

assuming it is not a leap year and number of days = 365 days

1 year = 365 x 24 x 60 x 60 = 31,536,000 seconds

energy = power x time

energy = 208 x 31,536,000

energy = 6.6 x 10^{9} joules

5 0

3 years ago

If a train travels 80 miles north, 60 miles east, what’s the magnitude of its total displacement? Find the solution by drawing a

AnnZ [28]

Answer:

100 miles North East.

Explanation:

Please see attached photo for diagram.

In the attached photo, X represents the magnitude of the total displacement of the train.

Thus, we can obtain the value of X by using the pythagoras theory as illustrated below:

X² = 80² + 60²

X² = 6400 + 3600

X² = 10000

Take the square root of both side

X = √10000

X = 100 miles.

Therefore, the magnitude of the total displacement of the train is 100 miles North East.

8 0

3 years ago

What is (3.25 x 10^5) + (7.5 x 10^4)?

ivanzaharov [21]

Answer:

400000

Explanation:

So first solve one part:

(3.25 * 10^5)

(3.25 * 100,000)

= 325000

Then solve the next part:

(7.5 * 10^4)

(7.5 * 10000)

= 75000

Now lastly, add the two answers:

325000 + 75000 = 400000

Therefore,

(3.25 x 10^5) + (7.5 x 10^4) = 400000

5 0

2 years ago

Read 2 more answers

This roadblock is present when a person assumes they know what the other person is going to say and they are too impatient to wa

Westkost [7]

The answer is mindreading. Have a great day :)

6 0

3 years ago

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on an unknown temperature scale, the freezing point of water is -15°U and the boiling point is +60°U. develop a linear conversio

shutvik [7]

Answer:

Since this is a linear equation

y = m x + b or

U = m F + b is a linear equation

when ΔF = (212 - 32) = 180

and ΔU = (60 - (-15)) = 75

m = 75 / 180 = 2.4 if converting F to U and a = .417

U = .417 F + b

If F = 32 then U = -15 and

-15 = .417 * 32 + b

b = -15 - 13.3 = -28.3 and our equation becomes

U = .417 F - 28.3

Check: let F = 212

U = .417 * 212 - 28.3 = 60 as it should

5 0

1 year ago