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3 years ago

10

An athlete is working out in the weight room. he steadily holds 50 kg above his head for ten seconds which statement is true abo

ut this situation.
1 the athlete isn't doing any work because he doesn't move the weight.
2 the athlete isn't doing any work because he doesn't hold the weight long enough.
3 the athlete is doing work because he prevents the weight from falling down.
4 the athlete is doing work because 50 kg is a significant load to lift.

1 answer:

Andrews [41]3 years ago

5 0

Hi. The answer to your question is the first option.

The athlete isn’t doing any work because he doesn’t move the weight.

Hope this helps :))

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Answer: $1.8\°$

Explanation:

The diffraction angles $\theta_{n}$ when we have a slit divided into $n$ parts are obtained by the following equation:

$dsin\theta_{n}=n\lambda$ (1)

Where:

$d=3.4(10)^{-5}m$ is the width of the slit

$\lambda=540 nm=540(10)^{-9}m$ is the wavelength of the light

$n$ is an integer different from zero.

Now, the second-order diffraction angle is given when $n=2$ , hence equation (1) becomes:

$dsin\theta_{2}=2\lambda$ (2)

Now we have to find the value of $\theta_{2}$ :

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Then:

$\theta_{2}=arcsin(\frac{2\lambda}{d})$ (4)

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Finally:

$\theta_{2}=1.8\°$ (6)

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The clothes washer in your house consumes 470 kWh of energy per year. Price of the washer is $360 and the lifetime of the washer

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Answer:

$893

Explanation: the complete question should be

The clothes washer in your house consumes 470 kWh of energy per year. Price of the washer is $360 and the lifetime of the washer is 10 yrs. Energy price in your city is 9 cents per kWh. What is the lifecycle cost of the clothes washer? (assume a maintenance cost of $11 per year)

SOLUTION

Given:

The clothes washe power consumption (PC) is 470 kWh

Price of the washer (P) is $360

lifetime of the washer (L) is 10 yrs

Energy price in the city (E) is 9 cents per kWh (Covert to $ by dividing 100)

maintenance cost (M) is $11 per year

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3 years ago

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Answer:

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Explanation:

The given motion is an example of projectile motion.

Let 'v' be the initial velocity and '∅' be the angle of projection.

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Let 'g' be the acceleration due to gravity

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$v_{x}$ = v cos(∅)

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We know that for a projectile motion,

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Since there is no force acting on the golf ball in horizonal direction.

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∴ If α = 25° , then

β = 90-25 = 65°

∴ The required angle is 65°.

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