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3 years ago

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An object weighs 7.84 N when it is in air and 6.86 N when it is immersed in water of density 1000 kg/m3. What is the density of

the object?

1 answer:

kirill [66]3 years ago

3 0

Answer:

8000 kg/m^3

Explanation:

Weight in air = 7.84 n

Weight in water = 6.86 N

density of water = 1000 kg/m^3

Let d be the density of object

According to the Archimedes principle, when a body is immersed in a liquid partly or wholly, it experiences an upward force which is called buoyant force. The buoyant force is equal to the loss in weight of the body.

Loss in weight of the object = Weight of object in air - weight of object in water

Loss in weight = 7.84 - 6.86 = 0.98 N

Volume of body x density of water x g = 0.98

Let V be the volume of body

V x 1000 x 9.8 = 0.98

V = 10^-4 m^3

Weight in air = Volume of body x density of body x g

7.84 = 10^-4 x d x 9.8

d = 8000 kg/m^3

Thus, the density of body is 8000 kg/m^3.

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An ideal gas is allowed to expand isothermally from 2.00 l at 5.00 atm in two steps:

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Heat added to the gas = Q = 743 Joules

Work done on the gas = W = -743 Joules

$\texttt{ }$

<h3>Further explanation</h3>

The Ideal Gas Law that needs to be recalled is:

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$\texttt{ }$

<u>Given:</u>

Initial volume of the gas = V₁ = 2.00 L

Initial pressure of the gas = P₁ = 5.00 atm

<u>Unknown:</u>

Work done on the gas = W = ?

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<u>Solution:</u>

<h3>Step A:</h3>

<em>Ideal gas is allowed to expand isothermally:</em>

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$\texttt{ }$

<em>Next we will calculate the work done on the gas:</em>

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<h3>Step B:</h3>

<em>Using the same method as above:</em>

$P_2V_2 = P_3V_3$

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$\texttt{ }$

<em>Next we will calculate the work done on the gas:</em>

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$W_B = -2.00(5 - 3\frac{1}{3})$

$W_B = \boxed{-3\frac{1}{3} \texttt{ L.atm}}$

$\texttt{ }$

<em>Finally we could calculate the total work done and heat added as follows:</em>

$W = W_A + W_B$

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<h3>Learn more</h3>

Minimum Coefficient of Static Friction : brainly.com/question/5884009
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$\texttt{ }$

<h3>Answer details</h3>

Grade: High School

Subject: Physics

Chapter: Pressure

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