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aleksandrvk [35]

3 years ago

5

A straightforward method of finding the density of an object is to measure its mass and then measure its volume by submerging it

in a graduated cylinder. What is the density (in g/cm3) of a 220g rock that displaces 75.0 cm3 of water

1 answer:

Verizon [17]3 years ago

5 0

Answer: 2.9 $g/cm^{3}$

Explanation:

from the question we are given the following:

mass of rock = 220 g

volume of displaced water = 75 $cm^{3}$

the density of an object is gotten from the formula density = $\frac{mass}{volume}$

From the question, we were given the mass of a rock and volume of water the rock displaces.

When water is placed in a graduated cylinder and a rock is placed in the water, the volume of water the rock displaces is the increase in the reading of water after the rock has been put in it. The amount of water displaced is known as the volume of the rock.

therefore volume of the rock = volume of water displaced

density = $\frac{220}{75}$ = 2.9 $g/cm^{3}$

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Answer:

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Explanation:

We are given;

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Thus, we will be using equation of motion and we have;

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A) We want to find how long her feet is in air.. It means we want to find out the time to get to a distance of x1 and also the time to achieve the distance (x1 + x2) on free-fall.

Thus, using equation of motion;

v = u + gt

Again, g = -9.81

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Now, for the time taken to achieve the distance (x1 + x2) on free-fall, we will use the formula;

s = ut + ½gt²

Where s = (x1 + x2) = 1.8 + 0.4587 = 2.2587 m

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2.2587 = 0 - ½(-9.81)(t2)²

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(t2)² = 0.4605

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t2 = 0.6786 s

Thus, total time of feet in air = t1 + t2 = 0.3058 + 0.6786 = 0.9844 s

C) Velocity when feet hit the water would be given by;

v = u + gt

Where u = 0 m/s and t = t2 = 0.6786

Since it's in direction of gravity, g = 9.81 m/s

v = 0 + (0.6786 × 9.81)

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3 years ago

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