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nikitadnepr [17]

4 years ago

5

A box is held at rest by two ropes that form 30° angles with the vertical. The tension T in either rope is 42 N. What is the wei

ght (w) of the box?
36 N

79 N

86 N

73 N

62 N

1 answer:

iragen [17]4 years ago

7 0

<h3><u>Answer;</u></h3>

= 73 N

<h3><u>Explanation</u>;</h3>

Using the formula

2 T cos(30°) = w

Where; T is the tension on each string, while w is the weight of the box given by mg

Therefore;

W = 2Tcos 30°

= 2 × 42 cos 30°

= 84 cos 30°

= 72.74

<u> ≈ 73 N</u>

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Answer:

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Explanation:

Given that,

Distance between the slit centers d= 1.2 mm

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3 years ago

Two guitarists attempt to play the same note of wavelength 6.48 cmcm at the same time, but one of the instruments is slightly ou

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2 years ago

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3 years ago

A microwave oven operating at 1.22 × 108 nm is used to heat 165 mL of water (roughly the volume of a teacup) from 23.0°C to 100.

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Putting values in above equation, we get:

$E=\frac{6.625\times 10^{-34}J.s\times 3\times 10^8m/s}{0.122m}\\\\E=1.63\times 10^{-24}J$

Now, calculating the energy of the photon with 88.3 % efficiency, we get:

$E=1.63\times 10^{-24}\times \frac{88.3}{100}=1.44\times 10^{-24}J$

To calculate the mass of water, we use the equation:

$Density=\frac{Mass}{Volume}$

Density of water = 1 g/mL

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Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{165mL}\\\\\text{Mass of water}=165g$

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$q=mc\Delta T$

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c = specific heat capacity of water = 4.184 J/g.°C

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Putting values in above equation, we get:

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To calculate the number of photons, we divide the total energy by energy of one photon, we get:

$n=\frac{q}{E}$

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Putting values in above equation, we get:

$n=\frac{53157.72J}{1.44\times 10^{-24}J}=3.7\times 10^{28}$

Hence, the number of photons are $3.7\times 10^8$

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4 years ago