Ask question

Ask question

All categories

3 years ago

13

The block in the illustration is floating in water. Water has a density of 1.0 g/cm 3 and about 25 percent of the block is below

water. What is a good estimate of the density of the block?

2 answers:

expeople1 [14]3 years ago

7 0

0.75 g/cm3

let me know if I'm right~! =^-^= hope it helps~!

~Cecildoesscience

jonny [76]3 years ago

3 0

Answer;

0.25 g/cm^3

Explanation;

25 % of 1 g/cm^3

= 0.25 g/cm^3

Water's density is 1 g/ml. Objects with a density greater than 1g/ml will sink when placed in water.

Objects with a density less than one will float when placed in water. If a block has a density of 0.1g/cm3 it will float because it's density is less than 1.

The percent of the block that will be below the water depends on the density of the floating object. To find the percentage of the object below the water we just convert the density of the object as a percentage.

You might be interested in

nata0808 [166]

Answer:

2 m/s^2, west

Explanation:

Vf=final velcoity

Vi=initial velocity

t=timw

$a = \frac{vf - vi}{t}$

=

$\frac{15 - 25}{5}$

= - 2 m/s^2

The - changes direction and makes it opposite

2 m/s, west

3 0

2 years ago

Can someone help me?

Cloud [144]

What do we know that might help here ?

-- Temperature of a gas is actually the average kinetic energy of its molecules.

-- When something moves faster, its kinetic energy increases.

Knowing just these little factoids, we realize that as a gas gets hotter, the average speed of its molecules increases.

That's exactly what Graph #1 shows.

How about the other graphs ?

-- Graph #3 says that as the temperature goes up, the molecules' speed DEcreases. That can't be right.

-- Graph #4 says that as the temperature goes up, the molecules' speed doesn't change at all. That can't be right.

-- Graph #2 says that after the gas reaches some temperature and you heat it hotter than that, the speed of the molecules starts going DOWN. That can't be right.

--

4 0

2 years ago

A sphere of radius R contains charge Q spread uniformly throughout its volume. Find an expression for the electrostatic energy c

tensa zangetsu [6.8K]

Answer:

$E = \frac{3kQ^2}{5R}$

Explanation:

Let the sphere is uniformly charge to radius "r" and due to this charged sphere the electric potential on its surface is given as

$V = \frac{kq}{r}$

now we can say that

$q = \frac{Q}{\frac{4}{3}\pi R^3} (\frac{4}{3}\pi r^3)$

$q = \frac{Qr^3}{R^3}$

now electric potential is given as

$V = \frac{k\frac{Qr^3}{R^3}}{r}$

$V = \frac{kQr^2}{R^3}$

now work done to bring a small charge from infinite to the surface of this sphere is given as

$dW = V dq$

$dW = \frac{kQr^2}{R^3} dq$

here we know that

$dq = \frac{3Qr^2dr}{R^3}$

now the total energy of the sphere is given as

$E = \int dW$

$E = \int_0^R \frac{kQr^2}{R^3} (\frac{3Qr^2dr}{R^3})$

$E = \frac{3kQ^2}{R^6} (\frac{R^5}{5} - 0)$

$E = \frac{3kQ^2}{5R}$

7 0

3 years ago

How do scientific tests help determine the properties of substances

tino4ka555 [31]

It can help determine substances that appear similar but react differently under the same circumstances.

7 0

2 years ago

An open pipe of length 0.58 m vibrates in the third harmonic with a frequency of 939Hz. What is the speed of sound through the a

vaieri [72.5K]

363 m/s is the speed of sound through the air in the pipe.

Answer: Option B

<u>Explanation:</u>

The formula used to calculate the wavelength given as below,

$Wavelength (\lambda)=\frac{\text { wave velocity }(v)}{\text { frequency }(f)}$

$v=\lambda \times f$ --------> eq. 1

In power system, harmonics define by positive integers of the fundamental frequency. So the third order harmonic is a multiple of the third fundamental frequency. Each harmonic creates an additional node and an opposite node, as well as an additional half wave within the string.

If the number of waves in the circuit is known, the comparison between standing wavelength and circuit length can be calculated algebraically. The general expression for this given as,

$L=\frac{n \lambda}{2}$

For first harmonic, n =1

$L=\frac{\lambda}{2}$

For second harmonic, n =2

$L=\frac{2 \lambda}{2}=\lambda$

For third harmonic, n =3

$L=\frac{3 \lambda}{2}$

$\lambda=\frac{2 L}{3}$ -------> eq. 2

Here given f = 939 Hz, L = 0.58 m...And, substitute eq 2 in eq 1 and values, we get

$v=\frac{2 \times 0.58 \times 989}{3}=\frac{1089.24}{3}=363.08 \mathrm{m} / \mathrm{s}$

3 0

2 years ago